DELAWAREErosion &Sediment CONTROL HANDBOOK Contents ACKNOWLEDGEMENTS ............................................................................................................................................ i 1.0 Introduction 1.1 Background ......................................................................................................................................... 1-1 1.2 Regulatory Authority ..................................................................................................................................... 1-9 1.3 Delaware State Program Structure ........................................................................................................... 1-15 2.0 Principles of Erosion & Sediment Control (ESC) 2.1 Source Control Measures ............................................................................................................................ 2-1 2.2 Site Planning for Erosion & Sediment Control (ESC) ............................................................................... 2-4 Appendices 2-A Symbols ...................................................................................................................................... 2-A1 3.0 Standards & Specifications for Land Development Best Management Practices 3.1 Sediment Trapping Practices 3.1.1 Straw bale barrier ................................................................................................................. 3.1.1-1 3.1.2 Silt fence ................................................................................................................................ 3.1.2-1 3.1.2.1 Standard 3.1.2.2 Reinforced 3.1.2.3 Super 3.1.3 Sediment trap ....................................................................................................................... 3.1.3-1 3.1.3.1 Pipe outlet ................................................................................................................ 3.1.3-3 3.1.3.2 Stone outlet .............................................................................................................. 3.1.3-5 3.1.3.3 Riprap outlet ............................................................................................................ 3.1.3-7 3.1.4 Temporary sediment basin ................................................................................................. 3.1.4-1 3.1.5 Storm drain inlet protection ................................................................................................. 3.1.5-1 3.1.5.1 Type 1 3.1.5.2 Type 2 3.1.6 Culvert inlet protection ......................................................................................................... 3.1.6-1 3.2 Dewatering Practices 3.2.1 Portable dewatering practices ............................................................................................ 3.2.1-1 3.2.1.1 Portable sediment tank 3.2.1.2 Geotextile dewatering bag 3.2.2 Pumping pit........................................................................................................................... 3.2.2-1 3.2.2.1 Type 1 3.2.2.2 Type 2 3.2.3 Dewatering device ............................................................................................................... 3.2.3-1 3.2.3.1 Skimmer dewatering device 3.2.3.2 Pipe dewatering device 3.2.4 Dewatering basins ............................................................................................................... 3.2.4-1 3.2.4.1 Type 1 3.2.4.2 Type 2 6 TOC - 1 12/03 3.3 Water Control Practices 3.3.1 Temporary swale ................................................................................................................. 3.3.1-1 3.3.2 Temporary earth berm ........................................................................................................ 3.3.2-1 3.3.3 Vegetated channel ............................................................................................................... 3.3.3-1 3.3.3.1 Parabolic 3.3.3.2 Triangular/Trapezoidal 3.3.3.3 Channel pipe drain 3.3.3.4 Channel stone drain 3.3.4 Lined channel ....................................................................................................................... 3.3.4-1 3.3.4.1 Parabolic 3.3.4.2 Triangular/Trapezoidal 3.3.5 Diversion ............................................................................................................................... 3.3.5-1 3.3.6 Check dam ............................................................................................................................ 3.3.6-1 3.3.7 Subsurface drain .................................................................................................................. 3.3.7-1 3.3.8 Pipe slope drain ................................................................................................................... 3.3.8-1 3.3.9 Chute .................................................................................................................................. 3.3.9-1 3.3.9.1 Riprap 3.3.9.2 Gabion mattress 3.3.10 Riprap outlet protection ..................................................................................................... 3.3.10-1 3.3.10.1 Riprap outlet protection - 1 3.3.10.2Riprap outlet protection - 2 3.3.11 Rirap stilling basin ............................................................................................................... 3.3.11-1 3.4 Soil Stabilization Practices 3.4.1 Topsoiling .............................................................................................................................. 3.4.1-1 3.4.2 Slope treatment .................................................................................................................... 3.4.2-1 3.4.2.1 Benching 3.4.2.2 Grooving 3.4.2.3 Serrating 3.4.3 Vegetative stabilization ........................................................................................................ 3.4.3-1 3.4.3.1 Soil Testing .............................................................................................................. 3.4.3-3 3.4.3.2 Temporary stabilization ......................................................................................... 3.4.3-5 3.4.3.3 Permanent stabilization ........................................................................................ 3.4.3-7 3.4.3.4 Sodding ................................................................................................................ 3.4.3-15 3.4.4 Streambank & shoreline stabilization ................................................................................ 3.4.4-1 3.4.5 Mulching ............................................................................................................................... 3.4.5-1 3.4.6 Stabilization matting ............................................................................................................. 3.4.6-1 3.4.6.1 Slope 3.4.6.2 Channel 3.4.7 Stabilized construction entrance ......................................................................................... 3.4.7-1 3.4.8 Dust control ........................................................................................................................... 3.4.8-1 3.5 Waterway Construction Practices 3.5.1 Temporary waterway crossings ......................................................................................... 3.5.1-1 3.5.1.1 Temporary culvert ................................................................................................... 3.5.1-5 3.5.1.2 Temporary timber mat ........................................................................................... 3.5.1-7 3.5.1.3 Temporary bridge ................................................................................................... 3.5.1-9 3.5.1.4 Temporary ford ...................................................................................................... 3.5.1-11 6 12/03 TOC - 2 3.5.2 3.5.3 Stream diversion .................................................................................................................. 3.5.2-1 3.5.2.1 Utility crossing diversion pipe 3.5.2.2 Coffer dam 3.5.2.3 Diversion channel Turbidity curtain .................................................................................................................... 3.5.3-1 3.6 Pollution Prevention Practices 3.6.1 Construction site pollution prevention ................................................................................ 3.6.1-1 3.7 Misc. Practices 3.7.1 ESC for minor land development ......................................................................................... 3.7.1-1 3.7.2 Protection of trees in urbanizing areas .............................................................................. 3.7.2-1 APPENDICES A-1 Update notices A-2 Glossary A-3 Geotextile application guide A-4 Stabilization matting application guide A-5 Riprap and stone properties tables DESIGN GUIDES DG-1 FHWA HEC-15, Design of Flexible Channel Linings DG-2 FHWA HEC-14 Chapter XI, Riprap Basin DG-3 NRCS EFM Chapter 16, Streambank & Shoreline Stabilization SUPPLEMENTS S-1 Standards & Specifications for Highway Construction BMP’s S-2 Standards & Specifications for Hydromodification BMP’s 6 TOC - 3 12/03 This page left intentionally blank. 6 12/03 TOC - 4 ACKNOWLEDGEMENTS The editor acknowledges the following groups for their contributions. Without their efforts, this revision to the Delaware Erosion & Sediment Control Handbook would not have been possible: 6 Delaware Sediment & Stormwater Program Staff 6 Delegated Agency Staff 6 Peer Reviewers among the Regulated Community In addition, a special acknowledgement to the developers of the following documents which served as valuable resources for the revisions to this Handbook: 6 Illinois Urban Manual 6 Maryland Standards and Specifications for Soil Erosion and Sediment Control 6 Virginia Erosion and Sediment Control This Handbook has been revised with the intention that it will become a “living document”. That is, it has been structured in such a way that keeping the Handbook current and up-to-date will be much easier. As such, the Delaware Sediment & Stormwater Program will issue additions, deletions, updates, etc. as necessary. Notification of these changes will be posted on the Department of Natural Resources and Environmental Control’s Web site. In addition, a database will be developed containing contact information for those who have ordered the Handbook so that they can be notified of these changes. Anyone having questions, comments or suggestions for improving the Handbook should contact the following: Delaware Sediment & Stormwater Program Division of Soil and Water Conservation 89 Kings Hwy Dover, DE 19901 (Phone) 302-739-9921 (FAX) 302-739-6724 This Handbook was funded in part by grants from: USEPA Region 3, NPS Program and NOAA, 6217 Program 6 i 6/05 This page left intentionally blank. 6 6/05 ii 1.0 INTRODUCTION 1.1 BACKGROUND 1.1.1 THE EROSION PROCESS Soil erosion is the process by which the land’s surface is worn away by the action of wind, water, ice and gravity. Natural, or geologic erosion has been occurring at a relatively slow rate since the earth was formed, and is a tremendous factor in creating the earth as we know it today. The rolling hills of the Piedmont and the broad expanse of the Coastal Plain are both a result of the geologic erosion and sedimentation process in Delaware. Except for some cases of shoreline and stream channel erosion, natural erosion occurs at a very slow and uniform rate and remains a vital factor in maintaining environmental balance. Water-generated erosion is unquestionably the most severe type of erosion, particularly in developing areas; it is, therefore, the problem to which this handbook is primarily addressed. It is helpful to think of the erosive action of water as the effects of the energy developed by rain as it falls, or as the energy derived from its motion as it runs off the land surface. The force of falling raindrops is applied vertically, and force of flowing water is applied horizontally. Although the direction of the forces created is different, they both perform work in detaching and moving soil particles. Water-generated erosion can be broken down into the following types: Raindrop erosion is the first effect of a rainstorm on the soil. Raindrop impact dislodges soil particles and splashes them into the air (see picture below). These detached particles are then vulnerable to the next type of erosion. Sheet erosion is the erosion caused by the shallow flow of water as it runs off the land. These very shallow moving sheets of water are seldom the detaching agent, but the flow transports soil particles which are detached by raindrop impact and splash. The shallow surface flow rarely moves as a uniform sheet for more than a few feet on land surfaces before concentrating in the surface irregularities. Rill erosion is the erosion which develops as the shallow surface flow begins to concentrate in the low spots of the irregular contours of the surface. As the flow changes from the shallow sheet flow to deeper flow in these low areas, the velocity and turbulence of flow increase. The energy of this concentrated flow is able to both detach and transport soil materials. This action begins to cut small channels of its own. Rills are small but well defined channels which are at most only a few inches in depth. They are easily removed by harrowing or other surface treatments. Gully erosion occurs as the flow in rills comes together in larger and larger channels. The major difference between gully and rill erosion is a matter of magnitude. Gullies are too large to be repaired with conventional tillage equipment and usually require heavy equipment and special techniques for stabilization. 6 1-1 12/03 Channel erosion occurs as the volume and velocity of flow causes movement of the stream bed and bank materials. Figure 1-1 illustrates the five stages of erosion. Figure 1-1. Types of erosion (Source: Michigan Soil Erosion and Sedimentation Guidebook) 1.1.2 FACTORS INFLUENCING EROSION The erosion potential of any area is determined by four principal factors: the characteristics of its soil, its vegetative cover, its topography and its climate. Although each of these factors is discussed separately herein, they are inter-related in determining erosion potential. Soil characteristics which influence the potential for erosion by rainfall and runoff are those properties which affect the infiltration capacity of a soil and those which affect the resistance of the soil to detachment and being carried away by falling or flowing water. The following four factors are important in determining soil erodibility: 1. 2. 3. 4. Soil texture (particle size and gradation) Percentage of organic content Soil structure Soil permeability Soils containing high percentages of fine sands and silt are normally the most erodible. As the clay and organic matter content of these soils increases, the erodibility decreases. Clays act as a binder to soil particles, thus reducing erodibility. However, while clays have a tendency to resist erosion, once eroded, they are easily transported by water. Soils high in organic matter have a more stable structure which improves their permeability. Such soils resist raindrop detachment and infiltrate more rainwater. Clear, well-drained and well graded gravel and gravelsand mixtures are usually the least erodible soils. Soils with high infiltration rates and permeabilities either prevent or delay and reduce the amount of runoff. 6 12/03 1-2 Vegetative cover plays an extremely important role in controlling erosion as it provides the following five benefits: 1. 2. 3. 4. 5. Shields the soil surface from raindrop impact Root systems hold soil particles in place Maintains the soil’s capacity to absorb water Slows the velocity of runoff Removes subsurface water between rainfalls through the process of evapotranspiration By limiting and staging the removal of existing vegetation and by decreasing the area and duration of exposure, soil erosion and sedimentation can be significantly reduced. Special consideration should be given to the maintenance of existing vegetative cover on areas of high erosion potential such as moderately to highly erodible soils, steep slopes, drainageways, and the banks of streams. Topography. The size, shape, and slope characteristics of a watershed influence the amount and rate of runoff. As both slope length and gradient increase, the rate of runoff increases and the potential for erosion is magnified. Slope orientation can also be a factor in determining erosion potential. For example, a slope that faces south and contains droughty soils may have such poor growing conditions that vegetative cover will be difficult to reestablish. Climate. The frequency, intensity, and duration of rainfall are fundamental factors in determining the amounts of runoff produced in a given area. As both the volume and velocity of runoff increases, the capacity of runoff to detach and transport soil particles also increases. Where storms are frequent, intense, or of long duration, erosion risks are high. Seasonal changes in temperature, as well as variations in rainfall, help to define the high erosion risk period of the year. When precipitation falls as snow, no erosion will take place. However, when the temperature rises, melting snow adds to runoff, and erosion hazards are high. Because the ground is still partially frozen, its absorptive capacity is reduced. Frozen soils are relatively erosion-resistant. However, soils with high moisture content are subject to uplift by freezing action and are usually very easily eroded upon thawing. 1.1.3 SEDIMENTATION During a typical storm event, runoff builds up rapidly to a peak and then diminishes. Excessive quantities of soil particles are eroded and transported principally during these higher flows. During lower flows, as the velocity of runoff decreases, the transported materials are deposited to be picked up by later peak flows. In this way, eroded soil can be carried downslope, or downstream, intermittently and progressively from their source or point of origin. This process is known as sedimentation. It must be recognized that sedimentation is a process of dynamic equlibrium. A certain amount of sedimentation and sediment transport occurs in even the most stable streams and rivers. However, when man's activities change the sediment loads and/or the hydrology of a watershed, the streams can quickly go out of equilibrium. Although the stream will eventually adjust to these changes, many more tons of soil will be carried away from the banks and bed in the process, only to be deposited as sediment in downstream receiving waters. The potential environmental and economic impacts of this sediment are discussed in later sections. 1.1.4 EROSION AND SEDIMENT PROBLEMS ASSOCIATED WITH CONSTRUCTION SITES The principal effect land development activities have on the natural or geologic erosion process consists of exposing disturbed soils to precipitation and to surface storm runoff. Shaping of land for construction or development purposes alters the soil cover and the soil in many ways, often detrimentally affecting on-site drainage and storm runoff patterns and eventually the off-site stream and stream flow characteristics. Protective vegetation is reduced or removed, excavations are made, topography is altered and the removed soil material is stockpiled - often without protective cover. In effect, the physical properties of the soil itself are changed. The development process is such that many citizens of a locality may be adversely affected even by development of areas of only limited size. Uncontrolled erosion and sediment from these areas often causes considerable economic damage to individuals and to society, in general. Surface water pollution, channel and reservoir siltation and damage to 6 1-3 12/03 public facilities, as well as to private property, are some of many examples of problems caused by uncontrolled erosion and sedimentation. Potential hazards associated with development include: 1. A large increase in areas exposed to storm runoff and soil erosion. 2. Increased volumes of storm runoff, accelerated soil erosion and sediment yield and higher peak flows caused by: a. Removal of existing protective vegetative cover. b. Exposure of underlying soil or geologic formations which are less pervious and/or more erodible than original soil surface. c. Reduced capacity of exposed soils to absorb rainfall due to compaction caused by heavy equipment. d. Enlarged drainage areas caused by grading operations, diversions, and street constructions. e. Prolonged exposure of unprotected disturbed areas due to scheduling problems and/or delayed construction. f. Shortened times of concentration of surface runoff caused by altering steepness, distance and surface roughness and through installation of “improved” storm drainage facilities. g. Increased impervious surfaces associated with the construction of streets, buildings, sidewalks and paved driveways and parking lots. 3. Alteration of the groundwater regime that may adversely affect drainage systems, slope stability and survival of existing and/or newly established vegetation. 4. Creation of south and west directional exposure of property which may hinder plant growth due to adverse temperature and moisture conditions. 5. Exposure of subsurface materials that are rocky, acid, droughty or otherwise unfavorable to the establishment of vegetation. 6. Adverse alteration of surface runoff patterns by construction and development. Although streams and rivers naturally carry sediment loads, erosion from construction sites and runoff from developed areas can elevate these loads to levels well above those in undisturbed watersheds. It is generally acknowledged that erosion rates from construction sites are much greater than from almost any other land use. Results from both field studies and erosion models indicate that erosion rates from construction sites are typically about an order of magnitude larger than row crops, and several orders of magnitude greater than rates from well-vegetated areas such as forests or pastures (USDA, 1970, cited in Dillaha et al., 1982: Meyer et al., 1971). Wolman and Schick (1967) studied the impacts of development on fluvial systems in Maryland and found sediment yields in areas undergoing construction were 1.5 to 75 times greater than detected in natural or agricultural catchments. The authors summarize the potential impacts of construction on sediment yields by stating that “the equivalent of many decades of natural or even agricultural erosion may take place during a single year from areas cleared for construction (Wolman and Schick, 1967).” Similar impacts from storm water runoff have been reported in a number of other studies. For example, Daniel et al. (1979) monitored three residential construction sites in southeastern Wisconsin and determined that annual sediment yields were more than 19 times the yields from agricultural areas. Studies have examined the effects of road construction on erosion rates and sediment yields in forested areas. In northern Idaho, the erosion rate per 6 12/03 1-4 unit area of road surface averaged 220 times the erosion rate of undisturbed areas over a six-year period (Megahan and Kidd, 1972). Other studies have documented increased surface erosion following road construction, but at increases smaller than the 220-fold increase reported in the 1972 study (Megahan, 1984). A highway construction project in West Virginia disturbed only 4.2% of a 4.75 square mile basin, but this resulted in a three fold increase in suspended sediment yields (Downs and Appel, 1986). During the largest storm event it was estimated that 80% of the sediment in the stream originated from the construction site. As is often the case, the increase in suspended sediment load could not be detected further downstream where the drainage area was over fifty times larger (269 sq. mi.). Another study evaluated the effect of 290 acres of highway construction on watersheds ranging in size from 5 to 38 square miles. Suspended sediment loads in the smallest watershed increased by 250%, and the estimated sediment yield from the construction area was 37 tons/acre over a two-year period (Hainly, 1980). A more recent study in Hawaii showed that highway construction increased suspended sediment loads by 56-76% on three small (1-4 sq. mi.) basins (Hill, 1996). MacDonald et al (in press) estimated that at least 130 tons/acre had eroded in just four months from a newly-constructed and unpaved road network on St. John in the U.S. Virgin Islands. Yorke and Herb (l978) evaluated nine subbasins in the Maryland portion of the Anacostia watershed for more than a decade in an effort to define the impacts of changing land use/land cover on sediment in runoff. Average annual suspended sediment yields for construction sites ranged from 7 to 100 tons/acre and 0.07 to 0.45 tons/ acre respectively. A 1970 study conducted by the National Association of Counties Research Foundation found the potential impacts of urban and suburban development to be even more dramatic, concluding that sediment yields from construction areas can be as much as 500 times the levels detected in rural areas (National Association of Counties Research Foundation, 1970). Each of these studies identify construction sites as the specific source(s) of sediment. Daniel et al. (1979) identified flow, followed by flow rate, as the most influential factor controlling the sediment loadings from residential construction sites. In evaluating sub-basins at a scale of between 0.35 and 22 square-miles, Yorke and Herb (1978) determined that sediment yields from developed “urban land” were on the upper end of the range for cultivated land (3.7 tons/acre as compared to 0.65 to 4.3 tons/acre). However, the source of most of the sediment in the urban land streams was identified as stream-channel erosion, not the developed properties themselves. Other studies have shown that stream reaches affected by construction activities often extend well downstream of the construction site. For example, between 4.8 and 5.6 kilometers of stream below construction sites in the Patuxent River watershed were observed to be impacted by sediment inputs (Fox, 1974 as cited in Klein, 1979). The environmental and economic consequences of allowing such activities to go unchecked are discussed in the following sections. 1.1.5 ENVIRONMENTAL IMPACTS OF SEDIMENT Storm water discharges generated while construction activities are occurring have a potential for serious water quality impacts. The biological, chemical and physical integrity of the waters may become severely compromised. For example, a number of pollutants are preferentially absorbed onto mineral or organic particles found in fine sediment. The erosion and delivery of sediment into aquatic ecosystems is the primary pathway for delivering key pollutants such as nutrients (particularly phosphorous), metals, and organic compounds (e.g., Novotny and Chesters, 1989). It has been estimated that 80% of the phosphorous and 73% of the Kjeldahl nitrogen in streams is associated with eroded sediment (USDA, 1989, cited in Fennessey and Jarrett, 1994). Even more startling is the apparent ability of sediment to act as long term memory or storage media for toxicants. Studies show that pollutants such as DDT, DDE, PCBs and chlordane whose use has been banned or highly restricted, can still be found at detectable levels in sediment deposited years ago in the bottom of streams and rivers. Where construction activities are intensive, the localized impacts of water quality may be severe because of high pollutant loads, primarily sediments. Siltation is the primary cause of impaired water quality in rivers, and the 6 1-5 12/03 Everest et al. p.second largest cause of impaired water quality in lakes (Managing Nonpoint Source Pollution. In an aquatic environment. causes an increase in subsequent flood crests and a consequent increase in the frequency of damaging storm events. Construction sites can also generate other pollutants associated with wastes onsite such as sanitary wastes or concrete truck washout.. Urbanization of a watershed increases the impervious surfaces and increases the pollutant load. Paterson et al. D. Evidence is now beginning to mount that the ability of a stream to maintain its health is related to the impervious areas within its watershed. rivers.... and Baltimore showed that sediment yields from developing areas could reach 25. silts. impeding sight-feeding. smothering benthic organisms. 1987. Megahan. Introduction of coarse sediment (coarse sand or larger) or large amounts of fine sediment is also a concern because of the potential of filling lakes and reservoirs as well as clogging stream channels (e. 1994). For most construction sites the primary concern is fine sediment.000 to 50. rills (typically less than one foot deep). The aesthetic attraction of many steams. A 1969 study in Washington. Coarser-grained materials also blanket bottom areas to suppress aquatic life found in these areas. fishing. 1991). reducing habitat by clogging interstitial spaces within a stream bed. Excess sediments are associated with increased turbidity and reduced light penetration in the water column. EPA. especially along highways and railroads. EPA-506/9-90. the abrasive action of these materials in motion accelerates channel scour and has an even more severely deleterious effect upon aquatic life.. Large inputs of coarse sediment into stream channels will initially reduce stream depth and minimize habitat complexity by filling in pools (MacDonald et al. may initiate landslides. and reducing the intergravel dissolved oxygen by reducing the permeability of the bed material (e. Numerous studies have shown that fine sediment (fine sand or smaller) adversely affects aquatic ecosystems by reducing light penetration. 1992. Where currents are sufficiently strong to move the bedload..accelerated by these higher flood stages induced by sedimentation. however. 1984). lakes. Sediment fills drainage channels. Construction sites in steep areas or along streambanks.g. 1. as well as more long-term effects associated with habitat destruction and increased difficulty in filtering drinking water.1. boating.000 tons per square mile per year. One study suggests that once a watershed becomes 12% impervious. or other types of mass wasting events (e. in turn. and other water-related recreational activities has been seriously impaired or destroyed by bank cutting and channel scour . 1991). abrading gills and other sensitive structures. they could represent more than one-half of the sediment load carried by many streams draining small subwatersheds which are undergoing development. the quality of aquatic life has reached a critical threshold. 197). and plugs culverts and storm drainage systems. Excessive quantities of sediment cause costly damage to waters and to private and public lands. In these cases coarse sediment inputs may be of greatest concern. Meehan. Although these latter quantities may appear to be small compared to the total. debris flows.g. and fine sands is to reduce drastically both the kinds and the amounts of organisms present.C. Obstruction of stream channels and navigable rivers by masses of deposited sediment reduces their hydraulic capacity which. and approximately one billion tons of this sediment is actually carried all the way to the ocean.g. and sheetwash (Haan et al. 1993). the general effect of fine-graded sediments such as clays.6 ECONOMIC IMPACTS OF SEDIMENT Over four billion tons of sediment are estimated to reach the ponds. Approximately 10 percent of this amount is contributed by erosion from land undergoing highway construction or land development. and reservoirs used for swimming. 6 12/03 1-6 . and lakes of our country each year. and this is due to the fact that the primary erosion and transport processes are rainsplash. thus necessitating frequent and costly maintenance. Approximately 80. solvents. In addition to the financial cost of dredging. however. indirect pollution through drift.Petroleum products. navigable channels must be continually dredged and the cost of filtering muddy water preparatory to domestic or industrial use becomes excessive . dissolve. More recently. insecticides.S. the damage caused by erosion and sedimentation has been quantified in terms of dollars spent to dredge navigational channels. Acid rain can accelerate these processes.Nitrogen. Nutrients . 2. sealants.approximately $500 million dollars annually (in 1986 dollars). 3. loss of reservoir capacity and so on. 1.Galvanized metal. Every year in the United States about 497 million yd3 of material are dredged by the U. Trace Metals . decay. the disposal of dredged material has become more difficult with the passage of laws to protect the marine environment and the consequent dwindling supply of suitable places to put it. etc. amounts to millions of dollars each year.000 to 100. Responsible development requires that steps be taken to control erosion and sedimentation from construction sites in order to minimize the environmental and economic impacts associated with such activites. Army Corps of Engineers and private operators to create and maintain navigable waterways and harbors. and potassium are the major plant nutrients used for the fertilizing of new landscape at construction sites. These coatings and treatments contain metals which enter storm water as the surfaces corrode. and under some circumstances may constitute a violation of water quality standards. Pesticides . The added expense of water purification in the United States. Potential pollutants which are commonly associated with construction activities include: 1. Municipal and industrial water supply reservoirs lose storage capacity. because of sedimentation. painted surfaces. In the past. The State of Delaware also has an active dredging program which is mainly responsible for maintenance of the Inland Waterways system.) are used widely at construction sites and may be improperly 6 1-7 12/03 . or leach. the usefulness of recreational impoundments is impaired or destroyed. efforts have concentrated on the qualitative cost. or the transport of soil surfaces into water.000 to $448.Annual costs for removing this quantity of sediment from streets alone was estimated to range from $224. the natural processes of sediment deposition and shoaling would make many waterways and port facilities impassable by most large commercial and defense vessels. 4. flake. and pressure-treated lumber comprise many of the surfaces exposed to storm water as a result of construction activity. The unnecessary or improper application of these pesticides may result in direct contamination. we cannot escape the fact that human health and well-being is ultimately related to the environment in which we live.000 yd3 of material is dredged each year under this program at an estimated cost of $3 to $4 per yd3 (in 1997 dollars). The process of keeping these waters passable is an expensive one . phosphorus. pesticides.7 OTHER POTENTIAL NONSEDIMENT POLLUTANTS Research has shown that there are also potential nonsediment pollutants likely to be present in storm water in significant quantities.1. and other synthetic organic compounds (glues.and sometimes exorbitant. consideration of alternatives to dredging has become an issue with serious implications for this nation’s maritime trade and naval installations. Without such activity. Thus. This Handbook was developed to provide practitioners in the land development and construction industries with the current Best Available Technology (BAT) in order to meet that goal. It is very difficult to place a dollar figure on damage to the environment.000 per square mile at that time. Heavy use of fertilizers can result in the discharge of nutrients to water bodies resulting in excessive algal growth and eutrophication.Herbicides. Spills and Illegal Dumping of Construction Materials . and rodenticides are commonly used at construction sites. wood and paper materials derived from packaging of building products. aluminum. In addition to erosion and sediment controls. which can migrate into surface or ground water resources. and steel beverage cans. solid wastes resulting from the clearing and grubbing of vegetation. food containers such as paper. Deliberate dumping of these materials.stored and disposed. 6 12/03 1-8 . the application of diesel fuel to the contact surfaces of the “hot mix asphalt” application and transport vehicles is a common practice that should be discontinued immediately. or septic system regulations. 5. and sanitary wastes. the plan must address the other potential pollutant sources that may exist on a construction site. compliance with applicable state or local waste disposal. sanitary sewer. control of offsite vehicle tracking.Miscellaneous wastes include wash from concrete mixers. These controls include proper disposal of construction site waste. On parking lot or highway construction projects. is a direct violation of the CWA. Miscellaneous Wastes . and control of allowable nonstorm water discharges. Whether we can attain the goals of stormwater and watershed management will depend on whether existing laws can be revised to modernize them and make their goals more consistent with the goals set forth in later laws emphasizing environmental protection. which is designed to increase the ability of state programs to protect wetland resources. Water Quality Cooperative Agreements. public education. 6 Section 104(g) is intended to encourage the establishment or enhancement of state small community outreach programs. provides very limited funding for watershed planning priorities. 6 State Wetlands Program. reduction and elimination of pollution. especially with respect to reducing the impacts of stormwater on aquatic systems. which is a program to improve the environmental conditions of near coastal waters through the use of a watershed management approach. especially those related to the control of stormwater and CSO discharges. Eligible activities include the development and implementation of regional strategies in targeted areas.1 FEDERAL PROGRAMS There has been no single piece of Federal legislation drafted specifically to address problems associated with erosion and sedimentation. river corridor watershed management planning. and on how well we can use existing laws and integrate them into a watershed management program. 6 Assessment and Watershed Protection Support. Some program activities include special water quality studies.1. and monitoring in support of Section 305(b) reports. have goals which conflict with the holistic ecological goals of watershed management. some of these programs. and Section 404 program assumption assistance. Unfortunately. along with others. 6 Wetlands Protection Program funds activities in targeted watersheds such as advance wetland identification. Several of these programs. watershed protection demonstration projects. investigations of pollution control techniques. S.2 REGULATORY AUTHORITY 1. Special programs that are funded through Section 104 include: 6 Near Coastal Waters. state wetland conservation plans. since passage of the Federal Clean Water Act in 1972. Most of these programs address erosion and sedimentation problems through the management of stormwater. and enforcement. and pilot and demonstration projects to implement NPDES-related activities. However. have legal authorities and goals which conflict with the more recent multiple goals of stormwater management which include minimizing or preventing adverse environmental impacts. especially older ones. 6 1-9 12/03 . regionwide targeting.2. Listed below is an overview of several federal programs in effect at the time this Handbook was prepared. allows establishment of national programs for the prevention. numerous federal programs that affect the management and protection of water resources have been implemented by a wide variety of federal agencies. U. which either directly or indirectly impact the management of stormwater and other nonpoint sources of pollution. Environmental Protection Agency Clean Water Act of 1972 Section 104. Eligible activities include the development of new state wetland protection programs or the refinement of existing programs. allows the establishment of regulatory programs for point sources of pollution but exempts most agricultural activities. Information and Guidelines. permitting. and stormwater discharges operated by local governments with a population over 100. Section 319. Lake restoration projects typically include three phases: Diagnostic/Feasibility Study. watershed NPS management program implementation within targeted watersheds. the establishment. NPS control practice installation at demonstration sites. and a continuous state water planning process. training. Section 304. Section 303. enforcement. Water Quality Inventory. that will protect. and Post-Restoration Monitoring. requires EPA to biennially report to Congress on the environmental quality of the nation’s water resources including an identification of which waters are or are not meeting their designated uses. usually over a five year period. is for the establishment of projects and programs to control pollution sources to lakes and protect/restore the quality of lakes. Requires the regular review and. revision of water quality standards.Section 106. including construction sites. state lake water quality monitoring and assessment. 319. Eligible activities include identifying pollution control methods to protect and restore water bodies and monitoring programs conducted statewide or in targeted watersheds. Funded by a one percent set aside of the state’s Title II grant funds. This includes basic program implementation tasks provided these activities help to institutionalize the program within a state. which are at least as stringent as those adopted by the EPA.000. authorizes the development of comprehensive conservation and management plans. technical assistance). is the successor to the Section 208 program conducted in the late 1970s and early 1980s. National Estuary Program. Being replaced by Section 604(b). Section 305. Clean Lakes Program. this program now includes certain stormwater discharges associated with specific industrial activities. if needed. States develop State Water Quality Assessment reports [305(b) reports] and submit them to EPA which uses them as the basis for their report. Title II and VI) may be used. physical and biological integrity of all waters. Funding for this program is inadequate and relies upon very uncertain annual appropriations. This is the primary federal grant funding source for state water quality management programs. Eligible activities include nearly all aspects of the prevention and abatement of surface and ground water pollution (planning. Section 402. Section 320. maintain and restore the chemical. for specific legislatively designated estuaries. especially hazardous and toxic ones. is for the administration of programs for the prevention. Section 205(j)(1). Restoration/Protection Implementation Program. Permits for Dredged or Fill Material. authorizes water quality management planning programs by states. adopt and enforce water quality standards. 6 Section 404. Traditionally oriented at reducing pollution from point sources such as domestic and industrial wastewater discharges. requires states to develop. Eligible activities include identification and classification surveys of all publicly-owned lakes. and public education. Water Pollution Control. National Pollutant Discharge Elimination System. and elimination of water pollution. Only those activities that implement the state’s EPA approved Nonpoint Source Management Plan are eligible for funding. monitoring. Does not provide funding for the implementation of approved plans although other CWA funds (ie.10 . Requires states to develop a list of waters needing control strategies for toxic and other pollutants. allows the establishment of a regulatory program to control 12/03 1 . Water Quality Standards and Implementation Plans. Section 314. reduction. public education. allocation and enforcement of total maximum daily loads for certain water bodies. and ground water NPS assessment and management programs. Nonpoint Source Program Implementation. requires EPA and the states to establish water quality criteria and effluent guidelines for a wide variety of substances. sedimentation. is intended to restore and protect farmed wetlands or converted wetlands. typically as forests. and nutrient management. using permitting guidelines developed in coordination with EPA. public education. typically in targeted critical areas. S.11 12/03 . and financial assistance to eligible farmers to address soil. identification. water. Section 604. PL-566 Program). to identify cost-effective and acceptable point and nonpoint source controls. administered by the NRCS. and to develop implementation plans. this program has become more broadly oriented with greater emphasis on protecting and restoring water quality.the discharge of dredged or fill material into navigable waters (wetlands). Eligible activities include projects to determine the nature. Conservation Reserve Program (CRP). Title VI Water Quality Management Planning. NRCS also has been publishing detailed soil surveys for each county in the country providing a wide variety of useful natural resources management information. Farmers receive payment on a per acreage basis to conserve these lands for a contracted period. Underground Injection Control. Provides grants to states to fund all types of activities related to this program. especially from problems related to flooding. provides technical and financial assistance to state agencies and local governments in the development and implementation of plans to protect. Federal Safe Drinking Water Act Section 1443. Resource Conservation and Development Program (RC&D). The purposes of the program are achieved through the implementation of a conservation plan. natural resources. U. Soil and Water Conservation. and reduce pollution sources. administered by the FSA. Farmers receive direct payments and conservation planning and technical assistance to install necessary restoration practices on those areas that they agree to maintain under a conservation easement. mapping and sampling of contamination sources. typically ten years. encourages and improves the capability of state and local entities in rural area to plan. requires each state to reserve one percent of the State Revolving Loan Fund grant for water quality management planning activities required by Section 205(j) and 303(e). and related natural resource concerns on their lands in an environmentally beneficial and cost-effective manner. administered by the FSA. provides technical assistance to the public through total resource planning and management to improve water quality. The program is funded through the Commodity Credit Corporation. Wetlands Reserve Program (WRP). educational. Section 1442. Recently. Five to ten-year contracts are made with prodicers and cost-share payments may be made to implement eligible conservation practices including animal waste management systems. and use/disposal of water. administered by the Natural Resources Conservation Service (formerly the Soil Conservation Service). erosion. and use the land and water resources in small watersheds. Watershed Protection and Flood Prevention (Small Watershed Program. is intended to return certain agricultural lands which are highly erodible or otherwise critical in protecting and restoring water quality to a conservation use. Department of Agriculture Environmental Quality Incentives Program (EQIP). Wellhead Protection. although the section allows a state to assume administration of the program. Eligible activities include delineation of WHP areas. This program is administered by the Army Corps of Engineers. and development of ordinances. develop. administered by the NRCS. buffer strips. provides technical. extent and causes of water quality problems. 6 1 . establishes federal and state programs to protect ground waters from these sources. provides technical assistance and funding to states and local governments designing and implementing wellhead protection programs. develop and implement programs. S. pursuant to Section 205 of the Flood Control Act of 1948. research and development (including BMPs). Projects must include mitigation of unavoidable environmental damages and must also consider environmental restoration through opportunities created with projects. Projects must provide for the long term conservation of these lands and waters. administered by the Fish and Wildlife Service. Coastal Wetlands Planning. development and management of the nation’s water resources. habitat and wildlife. typically structural ones such as bank hardening or dredging. consists of four water quality monitoring networks the most important of which is the National Stream Quality Accounting Network (NASQAN). The Surface Transportation Program component supposedly authorizes funding for highway stormwater quality controls and for mitigating damage to ecosystems. Provides funding to federal acquisition of authorized national park. However. the Corps is restricted to making improvements to natural water courses. authorizes the Corps to reduce flood damages through projects not specifically authorized by Congress. restoration. develop and improve outdoor recreation areas. Funds may be used for planning. Provides funding for erosion and sediment controls needed to minimize highway construction impacts but not typically for the treatment and management of highway runoff. was established to create and maintain a national legacy of high quality recreation areas. environmental restoration and water quality management. However. conservation and recreation areas and to state and local governments to help them acquire.U. Data on stream flow and height. administered by the Geological Survey. administered by the Geological Survey (USGS). Federal State Cooperative Program establishes a partnership for water resources investigations between the USGS and state and local agencies. coastal and shoreline erosion. roadside beautification and wetland mitigation. enhancement or management of coastal wetland ecosystems. lake stage and storage. will address a wide range of major water quality issues. This program is the foundation for much of the planning.12 . interconnected transportation system. 12/03 1 . and can not consider watershed stormwater improvements. ground water levels. administered by the National Park System. Water Data Program. Federal Highway Administration Federal Aid Highway Program assists state agencies in the development and improvement of an integrated. with special emphasis on pesticide impacts on water resources. Protection and Restoration Program. Department of the Interior National Water Quality Assessment Program. Land and Water Conservation Program. Army Corps of Engineers Civil Works Projects are a specific line-item congressional appropriation in the biennial Water Resources Development Act. The following programs have great potential to adversely affect aquatic systems and to impede the management of stormwater to protect or restore water quality: 6 Small Flood Control Projects. The program will include nationwide surface and ground water quality monitoring and assessment. provides funds for the acquisition of coastal lands or waters and for restoration. well and spring discharge and the quality of surface and ground waters is collected and stored in WATSTORE. Provides help to communities on a variety of water resource problems including flood control. provision for public access. protection of public health and safety. In addition DNREC was attempting to implement a regulatory program through a conduit that had been historically a service oriented technical advisory agency. significant negative impacts to the environment were still occurring as the result of land development. At this time the State passed its first law to address erosion and sediment control on developing lands. National Estuarine Research Reserve System allows establishment and management of a national system of reserves representing different coastal regions and estuarine types. This is when the environmental impacts of large scale development began to become apparent. and Delaware’s Erosion and Sediment Control Program was initiated. and siltation of navigable stream channels were just a few of the impacts that resulted. During this time there was a tremendous increase in the number of housing units and associated commercial developments being constructed in Delaware. Watershed Protection: Catalog of Federal Programs. and economic development.2 DELAWARE STATE PROGRAM The State of Delaware’s initial effort at implementing a statewide erosion and sediment control program dates back to 1978. EPA-841-B-93-002. 1993. National Marine Sanctuary Program allows identification of areas of the marine environment of special significance and provides authority for comprehensive and coordinated conservation and management of these areas. Coastal Nonpoint Pollution Control Program.C. Office of Water. allows the design and construction of flood control measures which typically increase drainage and decrease water quality. Washington D. States with federally approved CZM Programs must develop and implement programs to restore and protect coastal waters which include compliance with the minimum NPS management measures. Degradation of water quality. States with federally approved programs receive federal grant funds to develop and implement a wide variety of coastal resource management initiatives. 6 1 . is jointly administered with EPA which is responsible for establishing minimum NPS management measures. This type of program was new to the Districts and they found themselves in the non-traditional role as quasi regulators in implementing the program. During the 1980’s. 1. Delaware experienced an extended period of robust economic growth. Information Sources EPA.13 12/03 . The program was developed by the Delaware Department of Natural Resources and Environmental Control (DNREC) and implemented through the local conservation districts. Provides for research and monitoring activities and for public education. National Oceanic and Atmospheric Administration The Coastal Zone Management Act of 1972 This act allows states to prepare and implement comprehensive management programs for coastal resources which balance competing demands on resource protection. Section 6217.2. The reserves serves as field laboratories and as public education centers. flooding.Snagging and Clearing for Flood Control. This combination. Despite the fact that Delaware had an erosion and sediment control program. In 1980 the associated regulations were adopted. was started with high hopes. although unusual at the time. pursuant to the Flood Control Act of 1937. impacted industries. then Governor Michael Castle signed Senate Bill 359 enacting the Delaware Sediment and Stormwater law. 1991. With the passage of this law. as detailed in the law and regulations. Delaware’s program provides for implementation of control practices that function from the time construction is initiated through the life span of the project. The statewide legislation was unanimously approved by four legislative committees and on the floor of both the State Senate and the House of Representatives. 6 The basic premise of the program is that erosion and sediment control during construction. and a voluntary compliance attitude. and the general public needed to be convinced that a problem existed. the existing law and program were ineffective. and consultants. limited resources.A combination of factors including a tremendous increase in workloads. 1991.14 . the water quantity and quality impacts of permanent land use alterations were not being addressed by the State’s existing program. After going through the required public hearings and receiving no negative comments the regulations were approved January 23. Through a unique process as provided for in the law. plus stormwater quantity and quality control after construction are all components of an overall stormwater management program. The initial emphasis of the program was to prevent existing flooding or water quality problems from worsening. led to a program that fell short of its goals. The Conservation Districts were instrumental in supporting the legislation. Program implementation began on July 1. such as contractors. homebuilders. 12/03 1 . and that there was a need for a comprehensive approach to sediment control and stormwater management. On June 15. are adopted in the future. 1990. Prior to the submission of the proposed legislation regarding erosion and sediment control and stormwater management. By the late 1980’s there was a recognition by DNREC and the conservation districts that the existing program had failed to address or mitigate for water quality degradation and flooding caused by up-stream land development activities. Delaware became the first state in the nation to have a single Sediment and Stormwater law that clearly addresses both water quantity and water quality concerns. assisted the DNREC in developing the complementing regulations. The intent is to limit further degradation of the State’s water resources until comprehensive watershed specific approaches. Elected officials. representatives of the DNREC conducted an extensive educational program to document the serious nature of water quantity and water quality problems that existed statewide. It is anticipated that the program will continue to evolve as future challenges in protecting the State's water resources arise. Problem documentation was crucial to the success of the new program. In addition to these shortcomings. a regulatory advisory committee representing regulated groups and industry. Failure to accurately record site conditions or failure to notify either the contractor and or developer or inspection agency of site deficiencies may jeopardize the designated inspector’s certification which could be grounds for enforcement action against the contractor and or developer. The four program components that may be delegated are: 6 6 6 6 Sediment control and stormwater management plan approval Inspection during construction Post construction inspection of permanent stormwater facilities Education and training Unless specifically exempted in the regulations (Agriculture. DNREC is responsible for implementing the sediment and stormwater program.15 12/03 . These inspectors must attend and pass a DNREC course on inspection. 1. NPDES. The program is a fee based program that charges land developers a fee on a disturbed acre basis for plan review and inspection services. The inspection agency still must periodically inspect the site to ensure the adequacy of site controls. This course is approximately 4 hours long and acquaints contractors with the importance of good on site erosion and 6 1 .3. Another important feature of the regulations is the requirement that contractors must have a responsible individual(s) certified as having attended a DNREC course for sediment control and stormwater management.) There are a number of features of the Delaware Sediment and Stormwater Program that are unique with respect to other state or local programs. and submit an inspection report to the developer and or contractor and the inspection agency on their findings and recommendations. It has been demonstrated that this level of performance can be achieved with the application of present technology.2 DELAWARE SEDIMENT AND STORMWATER REGULATIONS The guidelines for implementing the Delaware Law under Chapter 40. depending on their ability to implement them. Sediment control and stormwater inspectors must be provided by the land developer on environmentally sensitive areas or larger projects (over 50 acres in size or where the State or delegated inspection agency requires) to assist the appropriate governmental inspection agency. and local conservation districts and jurisdictions may request delegation of various program components.3.1 PROGRAM ELEMENTS In Delaware. delegation must be reapplied for and approved by DNREC. at the end of this period.3 DELAWARE STATE PROGRAM STRUCTURE 1.1. A major unique feature of the Sediment and Stormwater Program is the use of private consulting inspectors (Certified Construction Reviewers). inspect active construction sites at least once a week. but the designated inspector will reduce the frequency of inspection for the inspection agency. The Regulations require that stormwater management practices achieve an 80 percent reduction in suspended solids load after a site has been developed. (NOTE: A copy of the current Regulations is maintained on the Sediment & Stormwater Program's Web site. CSO’s) any land disturbing activity that disturbs 5000 square feet or more must have an approved sediment and stormwater plan prior to commencing earth disturbing activities. Long term removal rates in excess of 80 percent may require extraordinary measures such as water re-use that may be required on a local basis but which is not practical from a statewide perspective. Title 7 are contained in the Delaware Sediment and Stormwater Regulations. the structure of the sediment and stormwater program is based on the fact that ultimate responsibility for the program rests with the State. Delegation of program elements is good for a period not to exceed three years. educational training. (NOTE: A copy of the current delegation structure and contact information is maintained on the Sediment & Stormwater Program's Web site. In the primarily urban county (New Castle) city government.) To date. This arrangement has created a partnership between State and local program implementers.16 .3. DNREC will then be responsible for collecting and maintaining the NOI’s. the Delaware Department of Transportation (DelDOT) has requested and received delegation for implementation of the plan review and inspection components of the sediment and stormwater program for highway construction and maintenance projects.4 INTERACTION WITH THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) Another unique feature of the Sediment and Stormwater Program is the interaction with the Federal National Pollutant Discharge Elimination System (NPDES) general permits program. The criteria established by Delaware’s sediment and stormwater program meets all requirements established by EPA for the NPDES General Permit for Construction Activity. and enforcement while the conservation districts and local governments provide actual program implementation. The establishment of a regulatory advisory committee is another feature of the program required by law. and the conservation district. This suggests that implementation of these program elements is an appropriate role for a State agency. no delegated agency requested delegation for education. training. In addition DNREC is responsible for program implementation on all hazardous materials and Superfund sites within the State. review.sediment control and stormwater management and their responsibilities according to the law and regulations. and provide “one stop shopping” for the regulated community. The conservation districts have taken the lead in Delaware in implementing the State’s sediment and stormwater program. 6 The requirement for a Notice of Intent (NOI) has been incorporated into the sediment and stormwater programs application. 1. or enforcement. During the first year of this program over 1500 individuals attended this course and were certified. The conservation districts and other delegated agencies will collect the NOI’s when applicants apply for a sediment and stormwater permit. DelDOT has made a major commitment to this program and their efforts have produced some outstanding results.3 PROGRAM DELEGATION The Sediment and Stormwater Regulations provide for delegation of program components to conservation districts or local government with DNREC acting as a safety net if any aspect of a delegated component is not adequately implemented. In addition a large number of DelDOT design. They are responsible for assisting with the development of the regulations and any changes or modifications to the law or regulations in the future. The contractors certification course is extremely popular with contractors and helps to reduce the “we-they” problems that often exist in regulatory programs. the Sediment & Stormwater Plan contains all the elements of the NPDES Stormwater Pollution Prevention Plan (SWPPP).3. 1. and maintenance staff have successfully completed DNREC’s contractors certification course and certified construction reviewers course. 12/03 1 . In a unique arrangement. This committee is composed of representatives of the regulated community and others affected by the law. It is understood that the NOI does not provide coverage until received by DNREC and will remain in effect until the Notice of Termination (NOT) is received. In addition. are implementing the plan review and inspection components of the program in their jurisdictional areas. DNREC has retained delegation for plan review and inspection of State and Federal projects other than highway work. In the two primarily rural counties (Kent and Sussex) in Delaware the conservation districts are implementing the plan review and inspection components of the program. This approach to the NPDES program was taken because it afforded DNREC the ability to implement the requirements of the NPDES general permit program with a minimum amount of paperwork. with DNREC providing technical expertise. DelDOT has hired staff to do both plan review and inspection activities in order receive delegation. county government. a recommended approach for watershed protection will be developed in conjunction with local government that presents a strategy for future resource protection in these Designated Watersheds. it is expected that the next phase of program implementation will address stormwater management from a watershed perspective. and alternative land uses and stormwater controls will be considered along with their impact on water quality.6 PLAN REVIEW One of the major functions of the DNREC and its delegated agencies is that of plan review. The Sediment and Stormwater Program follows a detailed enforcement policy based on referrals from delegated agencies and complaints received from the general public. Although it is assumed that sediment and stormwater management plans have been prepared by qualified individuals.3. Penalties for violators can range from $200 to $10. wetlands restoration. are the focus of this Handbook.) In addition. and stream habitat and diversity standpoint. Construction reviewers have the authority to issue Inspection Reports and Notices to Comply in cases where sites may not be in compliance with the approved plan. The Sediment and Stormwater Regulations contain a “Designated Watershed” concept that allows for the design and construction of practices on a watershed basis that. and permanent practices for post construction runoff control. and other non-structural practices.3. The temporary Best Management Practices (BMP's) included in this Handbook represent the current best available technology (BAT) for the control of erosion and sedimentation occurring as a result of land disturbing activities associated with land development. 1. 1. Since the DNREC has developed a minimum standard for these plans through the Regulations. (NOTE: A copy of DNREC's current plan review policy is maintained on the Sediment & Stormwater Program's Web site. There are several requirements of the Regulations in addition to the traditional controls that are contained in the Handbook that are important to providing overall site control. In addition. Erosion and sediment control practices. All formal enforcement throughout the State of Delaware is handled by DNREC. temporary practices during construction. it also ensures there is State-wide consistency between the various delegated agencies. This encourages developers to consider “phasing” large projects.8 PROGRAM EVOLUTION As the program evolves and matures.3. reduces existing flooding problems or improves existing water quality. (NOTE: A copy of DNREC's current enforcement policy is maintained on the Sediment & Stormwater Program's Web site. For example. 1. no more than 20 acres may be disturbed at any one time. and a tool of last resort in order to achieve compliance.1. depending on the circumstances of the violation.3. Each day the violation continues constitutes a separate offense. the plan review process provides a QA/QC. unless modified for a specific project. when coupled with land use planning. water quality. They have been selected based on either past performance of in-field application or on research data from controlled experiments. temporary site stabilization must be accomplished if the disturbed areas are not being actively worked for more than 14 days. Section 2 contains detailed information on the preparation and presentation of sediment and stormwater management plans. site control practices are grouped into two categories. Therefore.17 12/03 .5 E&S CONTROLS AS TEMPORARY STORMWATER MANAGEMENT Under the Regulations. These watersheds will be studied from a hydrologic. Formal enforcement is viewed as a serious measure. a developer in one jurisdiction would not experience major differences in requirements were he/she to develop in another jurisdiction. 6 1 . On the basis of the results of the watershed study. designed for temporary site control.) A full time uniformed Environmental Protection Officer has been dedicated to the enforcement of this program.000 for each offense. policies and checklists.7 ENFORCEMENT It is widely recognized that in order to have a successful regulatory program there must be an enforcement component to deal with non-compliance. and municipal agencies and conservation districts. It represents a new approach toward implementing regulatory programs. 12/03 1 . However. a cooperative approach that emphasizes education and training will provide for greater program success than a strictly regulatory program that fosters an adversarial relationship. If maintenance of stormwater structures is to be assured. at this time maintenance is the responsibility of a community or homeowner’s association that may or may not be providing adequate maintenance. but that mechanism is used only when a cooperative approach cannot achieve compliance. This approach places a heavy emphasis on cooperation between State. This fee is expected to accompany the designated watershed concept as a mechanism to fund watershed studies and planning. education of the regulated and affected groups. residential maintenance is a problem. There is a viable enforcement option. The law and regulations provide a framework for the implementation of stormwater utilities (user fees) as an alternative to permit fees or general funding. County. This program goes far beyond just combining two regulatory programs into one.18 . implementing. 6 The sediment and stormwater program is Delaware’s first attempt at implementing a comprehensive stormwater management program that attempts to mitigate for the effects of land development. and a dedicated funding source such as a stormwater utility will have to be implemented. designing. Maintenance of commercial stormwater management structures has not and is not expected to be a significant problem. public maintenance. and maintaining stormwater management structures. and a working relationship between all parties involved in order to achieve resource protection. because one person or company is generally responsible for maintenance. One area that has not been satisfactorily addressed is the maintenance of residential stormwater management structures. In an era of budgetary constraints.Funding is another area that must be addressed if the sediment and stormwater program is to be expanded. 1 SOURCE CONTROL MEASURES Source control is the first opportunity in any nonpoint source control effort. Preventive maintenance inspections should be carried out by trained personnel or the designated SWPPP committee. or contractor activity. It is easily performed at a relatively low cost and may yield great savings in the long run. or replacement of parts. Examples of source control include: 1. Maintenance of all records of inspections and follow-up actions. Protecting natural hydrology. equipment. adjustment. Protecting wetlands or riparian habitat and other sensitive areas. 3. Identification of the equipment and systems to which the preventive maintenance program should apply. monthly inspections will be appropriate. In some cases. and any structural source controls already in place. Contractor-owned facilities. all vehicular and maintenance facilities. in conjunction with the construction activity manager. repair. facilities.0 PRINCIPLES OF EROSION & SEDIMENT CONTROL (ESC) 2. A testing schedule can be developed in the same manner. 2. such as equipment cleaning facilities. 4. Periodic testing of equipment and systems. and repair of their contractor-owned facilities and equipment. Appropriate adjustments. Periodic inspections of identified equipment and systems. Adjustments or repairs of any type to the equipment or systems must be completed by trained personnel. and maintenance records may be subject to review by the appropriate delegated agency 2.1. however. 2. Preventing interaction between precipitation and introduced pollutants. Reducing or eliminating the introduction of pollutants to a land area.2 RECOMMENDATIONS FOR A PM PROGRAM The preventive maintenance program should include the following: 1.1.2. 6 2-1 12/03 . Preventive maintenance includes inspection of construction activity/contractor equipment and systems. The inspection schedules should be established by the committee. Inspection frequencies can be established in part by reviewing any “Risk Identification and Assessment” studies that may have been completed for the construction activity.1 PREVENTIVE MAINTENANCE (PM) A Preventive Maintenance (PM) program is an effective and cost-efficient measure in pollution prevention. 5. and tank containment. such as drip pads. It is important that the personnel be familiar with the systems and equipment to be monitored and tested. 4. 2. Preventing nonintroduced pollutants (such as loose dirt and sediments) from leaving the site during landdisturbing activities. equipment. testing. sumps. Source control methods vary for different types of nonpoint source problems. 3. 5. and brought to the attention of all employees. testing frequencies will not need to be as often as inspection frequencies. Each contractor should be directly responsible for inspection. Safe and orderly storage of construction debris. Records of resulting maintenance and filing requirements. chemicals. grease. Delivery reduction practices intercept pollutants leaving the source by capturing the runoff or infiltrate. Special attention must be given to those portions of the equipment that come into contact with any suspected pollutant. A tracking or follow-up procedure will be used to ensure that the appropriate response to the inspection findings has been made. operations. Periodic training of employees in housekeeping techniques for those areas of the construction activity where pollutant sources are found reduces the significant material contamination of storm water. Cleaning protocols should be site-specific. tanks and associated valves. and equipment to be inspected.3 DELIVERY REDUCTION MEASURES 6 Pollution prevention often involves delivery reduction (intercepting pollutants prior to delivery to the receiving waters) in addition to appropriate source control measures. Checklists and procedures to be used. pipes.1. Particular attention should be given to remedying leaks and replacement of deteriorated rubber or plastic hoses. Disposal of these materials should be by qualified hazardous materials handling contractors. The equipment itself should be serviced in designated areas as indicated above. Material loading and unloading areas should be cleaned manually or with heavy equipment. The protocols should be developed to meet the site-specific requirements of the construction activity. Mechanism for revising protocols. solvent. pipes for liquid conveyance (including vacuum hoses for liquid extraction). Management measures include delivery reduction practices to achieve the greatest degree of pollutant reduction economically achievable. Housekeeping practices include: 6 6 6 Maintenance of material loading/unloading areas. oil. 2. Good housekeeping is an important component of the pollution prevention plan. nozzles. among others: trams or conveyor mechanisms.Documentation and retention of records is a critical element of a good preventative maintenance and inspection program. as required by NPDES regulations. These portions include. Maintenance areas should be kept clean. Records of inspection and filing requirements. Chemicals. Good housekeeping refers to the cleaning and maintenance practices conducted at the construction activity. and tank seams. and other significant materials. The protocols should fit the nature of construction activity (and tenant organizations). Liquids should be removed using absorbent materials or with vacuum machinery. The protocols should cover: 6 6 6 6 6 6 Areas. Frequency of inspection. and fuel spills should be collected by use of absorbents and booms where necessary. All inspection documentation and records must be maintained with the SWPPP documentation for a period of 3 years following final stabilization. followed 12/03 2-2 . fittings. Inspection and maintenance guidelines for construction equipment should follow the manufacturer’s specifications. Stimulating employee interest in good housekeeping. washers. and gaskets. because of their infiltration properties. 6 2-3 12/03 . filter strips may be effective for controlling particulate and soluble pollutants where sedimentation is not excessive. although highly successful at controlling suspended solids. and proper maintenance. The performance of delivery reduction practices is to a large extent dependent on suitable designs. be suitable for use in areas with high ground water tables and nitrate or petroleum residue problems.either by treating and releasing the effluent or by permanently keeping the effluent from reaching a surface or ground water resource. but also increase infiltration to ground water. delivery reduction practices often bring with them side effects that must be accounted for. management practices that intercept pollutants leaving the source may reduce runoff. For example. By their nature. may not. In many cases. For example. filter strips are used as pretreatment or supplemental treatment for other practices within a management system. operational conditions. These devices. but may be overwhelmed by high sediment input. plan design. With limited exception. It is recommended that the designer discuss the ESC plan as early in the process with the plan review agency. This chapter will introduce the planning concepts and strategies necessary to incorporate erosion and sediment control practices into the comprehensive Sediment and Stormwater Management plan. A site planning overview. unless otherwise exempted.1 INTRODUCTION Subsequent chapters of this Handbook will contain discussion of specific sediment and stormwater management practices and the design applications of those practices. should begin as soon as possible in the site planning process. The State of Delaware Sediment and Stormwater Management law and regulations require that a Sediment and Stormwater Management plan be developed and approved before any land disturbing activity begins. State and Local permits and regulations that are necessary prior to project approval. the site designer will need to investigate all of the Federal. As technical information becomes more readily available in the public domain. The site plan designer will need to establish contacts with the local agencies that may offer technical assistance in the plan development phase. The minimum requirements contained in the State’s regulations will be adhered to. The Erosion and Sediment Control (ESC). Delaware Geologic Survey and Water Resources Agency. permanent stormwater management practices such as ponds and basins are utilized during construction for sediment control. and acquire those permits. public agencies have more data to share with site plan designers.2 SITE PLANNING MEASURES 2. technical information may be gathered by investigating specific state and local agencies. In many cases. The development of the plan however. and have well-developed plan submittal policies. Much of this data will be 12/03 2-4 . All plan review agencies will utilize a plan submittal checklist. and sample site plan examples will be presented in this chapter. The responsibility to know which permits are necessary. During the design of any project.2. The site designer will develop a comprehensive Sediment and Stormwater Management plan.2. and perhaps enhanced by the local review agency. erosion and sediment control management strategy. local planning and public works agencies. should address the runoff that takes place during the construction phase of the land development. State Department of Transportation. 6 In addition to local land use planning agencies. site-planning criteria. It is difficult to design an effective erosion and sediment control strategy without considering the permanent stormwater management practices. Soil and Water Conservation Districts. Universities and Colleges. with other permit requirements. review and submittal requirements will be different throughout the State. the plan review agency will not condition the Sediment and Stormwater Management plan approval. One focus of this chapter is to present the site planning process as an important component in developing an erosion and sediment control management plan. County Cooperative Extension Offices. State Economic Development Office. Knowing the agencies that have access to important baseline information on a particular land parcel will save the designer valuable time and resources in plan preparation. These include: The Delaware Department of Natural Resources and Environmental Control. As the State of Delaware delegates the Sediment and Stormwater program responsibilities to local agencies. is the responsibility of the project designer. not the approval agency. portion of this plan. The ESC measures that work in one particular phase will not necessarily be effective in a later phase. 2. the site planner / engineer will have investigated a myriad of land use regulations and guidelines.5 12/03 . but what happens when the builder begins to construct homes. Recognize the Need for Better Site Design Planning . and Inspectors as well. As has been mentioned previously in this manual. 4. Since the inception of the Sediment and Stormwater Program. is far less expensive than excavation costs to remove accumulated sediment from traps and basins.Many design consultants lack the technical expertise in subject areas such as soils and vegetation. and not a waste product that needs to be cleaned out of a trap or basin and disposed of. Think of a sediment trap that is located where a proposed building lot will be established. sediment and stormwater approach in site planning has been one that has evolved in recent years. the idea of comprehensive erosion. with large databases of technical information being developed through Geographic Information System (GIS) applications. but ESC design cannot be incorporated into the site plan as the last thought. There are several suggestions to designers that could improve the function of the ESC plan in the field. This evolution from providing sediment barriers at the perimeter of the site. 1. and that trap needs to be eliminated? This needs to be anticipated in the planning process. and re-defining or modifying development standards. zoning codes and local ordinances. Recognize Site Work is a Dynamic Process . This thought will be explained in greater detail later in this section. infrastructure needs. Contractors. designers need to consider ESC strategies in each step. federal. Improve Technical Knowledge of Erosion and Sediment Control Basics . Of equal importance. The trap may be effective during the bulk grading phase. 2. but less expense in the site work as well. incremental and final stabilization efforts. Recognize Erosion Control is Often Overlooked . need to be reminded that the minimization of soil erosion should be of equal importance to the sediment control portion of the ESC plan. a sufficient knowledge of plant materials is critical to design a plan that addresses temporary. To integrate erosion and sediment control into the site plan.in electronic and digital formats.There is a significant effort to select the proper Best Management Practice (BMP). the shortcomings in plan development are recognized as problems that surface in the field during development. and soil amendments necessary for establishing the correct vegetation. state and local environmental permit requirements as well as the physical and environmental considerations of the land to be developed. In some cases it will be necessary to develop a separate plan for different phases of development. Not only will this translate to less soil erosion. to providing a comprehensive planning approach which considers reducing erosion potential as a means of resource protection. properties of soils in suspension. 3. and be expected to be effective.2.2 BASIC PRINCIPLES OF EROSION AND SEDIMENT CONTROL (ESC) SITE PLANNING Before any of the erosion and sediment control management practices that have been discussed in previous chapters may be considered. Consider the soil as a resource. This may mean re-assessing some traditional site planning standards. Knowledge of soil properties must go beyond the understanding of geotechnical properties. has changed the way that practices are selected and used. Professionals in ESC design must understand soil erodibility. If the plan designer does not have adequate technical knowledge 6 2. Establishing vegetation to hold soil in place.Designers. all of the above need to be considered and recognized as factors that will guide the ESC management strategy. As the site plan develops in the early phases. and maintaining or improving water quality. In an article reprinted in the Minnesota Stormwater Manual. there is a structure to roles and responsibilities among DNREC and the delegated agencies in the county and municipal areas. Natural drainage systems. 4. Confine Development and Construction Activities to the Least Critical Areas . stream corridors and buffer areas should be preserved and utilized in the erosion.Roads. Reproduce Pre-development Hydrologic Conditions . for sediment and stormwater program implementation. and plan review procedures. This is a goal that can only be achieved comprehensively at the level of site planning. as site design becomes more complex. 6 Specifically. and all local agencies have checklists for plan submittal. It means looking at reproducing. 3. Similarly. goals must be established that directs the development of the ESC plan. These collaborative efforts are becoming more common. Plan submittal checklists assist the designer in knowing the specific requirements of each governing agency. Sykes ASLA. Minimizing dramatic alterations in the topography will make the design. To develop site plans that minimize adverse impacts to receiving waters. Robert D.Designing site conditions to best utilize the existing site topography obviously makes the best economic sense for the site developer. that may serve as a source of technical information. but in many cases it is the judgement of the site designer to leave critical areas undeveloped. there are agencies such as the Soil Conservation Districts and Cooperative Extensive Agencies mentioned earlier. infiltration capacity. ground water recharge. The impact that site development has on these hydrologic conditions. the specific plan requirements may change significantly from one local jurisdiction to the next. the full spectrum of hydrologic conditions: peak discharge. Preserve and Utilize the Natural Drainage System . the site designer is challenged to choose an erosion. These would include shorelines. land surveyors or landscape architects often partner with engineers and environmental consultants to design a complete site plan package.in these areas. erodable soils and natural drainageways to name several. runoff volume. implementation and maintenance of erosion and sediment controls an easier process. will depend in large part on the amount of impervious area created and the location of this impervious area to drainage paths and vegetative cover. the consideration of stormwater management will determine the effectiveness of the erosion and sediment control strategy selected. while providing natural filtration and minimizing impacts to adjacent sensitive areas. sediment and stormwater plan to facilitate drainage.Minimize the adverse impact of development on water quality and the hydrologic site conditions by avoiding construction or land disturbance in the most sensitive areas. buildings and other impervious areas should be sited high in the landscape and along ridges wherever possible. base flow levels. A plan designer with a structural or civil background can team up with experts in the areas mentioned above. 1. serve as the root for sound erosion and sediment control planning. By realizing that site development is a dynamic process. as nearly as possible. (NOTE: A copy of DNREC's current plan review checklist is maintained on the Sediment & Stormwater Program's Web site. 2. steep slopes. Fit Development to the Terrain . Some state and local restrictions to development in these areas may apply. The designer should be aware that although the State Sediment and Stormwater Regulations serve as a framework for the local agency programs. in Delaware.) 12/03 2-6 .Remembering that erosion and sediment control is stormwater management during construction. identifies some of the more important goals that although general. sediment and stormwater management strategy that will accommodate the changing landscape of the site during all phases of construction. 3 EROSION AND SEDIMENT CONTROL PLAN DEVELOPMENT The ESC plan is the cornerstone of successful implementation. which greatly facilitates this aspect of the plan preparation. which are applicable for all land disturbing activity.2. the planning process begins with data collection. even with the most well intentioned construction team if the ESC plan has not been thoughtfully prepared.2. 2. A variety of sources exist for assistance with mapping. and will result in a stop work order. Obviously. as well as possible enforcement action. Several key components of the Regulations are worth emphasizing. as well as planning staff at the local level. wetland identification and existing land use. 6 Approved plans must be kept on site at all times. there are some regulatory requirements at the State level. 6 Plans are required to be approved before any local building or grading permits are issued. Preliminary construction drawings should never be used as a substitute for the approved plan. a plan must have the stamp and signature of the plan approval agency. 6 2. Resource protection cannot be realized however. To be considered approved. PLAN DESIGN å PLAN APPROVAL å PRE-CONSTRUCTION MEETING å PLAN IMPLEMENTATION å ENVIRONMENTAL PROTECTION These are the steps necessary to complete the cycle from design to resource protection. soil surveys. 6 Approved plans are valid for three years unless extended by the plan approval authority. These include both Federal and State agencies. 6 Approved Sediment and Stormwater Plans are required for all land disturbing activities unless exempted under the Regulations. 2. Starting construction without the approved Sediment and Stormwater Plan on site is a violation of the State law and regulations.Although specific plan requirements may change.4 DATA COLLECTION AND PRELIMINARY ANALYSIS Before any information may be transferred to paper. Each is dependent on the other to have a complete effort in the ESC management strategy. the actions of the site developer and contractor will determine in large part the extent to which the plan is implemented. It is becoming more and more common for these organizations to make their data available to the public through the Internet.7 12/03 . Site planning criteria will identify the site characteristics that determine the ESC planning and design choices. For instance. required re-zoning etc. mention whether a project will need special permits. Also include any discussion of site design or layout that would facilitate least critical area development. The very basic elements for investigation include: Site Information Background Location Vicinity Map Zoning Prior Land Use Present Land Use Proposed Land Use Surrounding Land Use Project Description Expand the discussion of the proposed land use to better identify the development project. or planning considerations that would minimize creation of impervious areas. This would also be an appropriate place to describe the phasing of a project. Data Analysis Watershed and Drainage Area information Climate Geography / Geology Elevation and Slopes Soils Information/Description Hydrology / Hydraulics Stormwater Computations Natural and Improved Drainage Systems Off-Site Drainage Existing Vegetation Physical / Environmental Site Limitations 6 Spatial Limitations Open Space Requirements Steep Slopes Erosive Soils Protected Recharge Areas Wetlands Floodplain/Floodway Areas Stream Corridor/Buffer Areas Forested Areas 12/03 2-8 . it is advised to include a copy of the design report with the approved sediment and stormwater plan. Site Description . Stormwater and Drainge Information . etc. The Erosion and Sediment Control portion of that plan needs to guide the land developer and contractor from the beginning of land disturbing activity to the completion of the project. housing lots. etc.9 12/03 . so that the project may continue beyond the original twenty acres.Wetlands.Phasing. zoning. but hardly a comprehensive effort. permeability. suitability. 3. is to determine the scope of the plan. existing erosion. existing use.Hydrologic computations. This may have made development of an erosion and sediment control plan easier. Geotechnical Considerations . and other appropriate information. utility conflicts. the next task facing the site designer in the preparation of the ESC plan. 4. sreams.The Delaware Sediment and Stormwater Regulations section 10 details the phasing requirements that restrict grading more than 20 acres at once. etc. The 1991 Sediment and Stormwater Regulations require that both temporary and permanent stormwater strategies be developed in the early stages of the site planning process. Location of the erosion and sediment controls are shown on a separate plan sheet along with roads. The site designer must incorporate a temporary stabilization program with the phasing requirements. soils. infiltration. Although this material is supplied by the design consultant to the plan reviewer as background or supporting information. Environmental Considerations .Topography. a site designer would usually overlay the erosion and sediment controls on the existing site plan. Construction Description . 5. proposed construction schedule.Soils. Project Description . proposed use. drainage maps. 2.Location. and can usually be identified as: 1. After the preliminary data and survey information is collected and analyzed. utilities. etc. etc. etc. When ESC plans were first developed.2. 6 2. 2.Water Table Depth to Bedrock Flora and Fauna Areas of Cultural and Historic Significance Streams and Waterbodies Existing Utilities A design report will typically accompany the information on the plan sheets. Will this be the first phase of a multiphase project? Phasing Requirements . physical features.5 PREPARING EROSION AND SEDIMENT CONTROL PLANS The set of 24” x 36” plan sheets typically associated with construction site drawings is the Sediment and Stormwater Plan. 6. Residential Development – Large Scale a. As such. with limited right of way.Designing for the Specific Type of Land Development . will determine the ESC strategy. Special attention will be needed to include both construction details and methods of construction for waterway construction. In developing ESC plans for DelDOT highway construction. stream. or drainage channel will be impacted. 3. Residential Development – Small Scale a. DelDOT has a well-developed plan review and inspection policy and procedures that must be followed by all persons that are involved in the design or construction of ESC plans. Field Services Section. existing road expansion.6 DELAWARE DEPARTMENT OF TRANSPORTATION (DELDOT) HIGHWAY CONSTRUCTION PROJECTS DNREC has granted DelDOT delegation authority for Sediment and Stormwater plan review and construction inspection for all DelDOT highway construction projects. Bulk Grading b. Site Improvements c. It may be necessary to obtain temporary construction easements for control practices such as sediment traps. Final Stage 5. 6 This will pose challenges to the ESC designer. The linear nature of these projects increases the likelihood that a waterway. only enough right of way is acquired to complete the required construction. This can make it difficult to maintain ESC practices once they are constructed.10 . Proper ESC planning 12/03 2 . they all share similar challenges to the ESC plan designer. 6 When an existing roadway is under construction. Bulk Grading b.The type of land development project being undertaken. as lanes will be shifted. to shoulder widening and overlay projects. DelDOT Highway Construction Projects Utility Construction Commercial/Industrial Development – Small Scale Commercial/Industrial Development – Large Scale a. the consultant needs to acquire the DelDOT Standards and Specifications and Detail Drawings that have been developed specifically for DelDOT. intersection and drainage improvements and bridge re-construction. and efforts undertaken to minimize the time delay in temporary construction. Some of the design considerations will be discussed for: 1. Site Improvements c. 6 The construction project is usually linear in nature. The use of tire wash facilities and street brooms may also become part of the ESC plan. General Permit for Individual Home Construction 6. Usually. Home Construction 2. 4. The ESC plan will need to address the issue of highway safety from sediment leaving the construction area. In addition to becoming familiar with the details and specifications contained in this Erosion and Sediment Control Handbook. Roads Only Plans b. These documents are available from the Delaware Department of Transportation. as well as the phase of construction. interim access roads constructed. traffic must continue around and through the work area. and employ a dust control strategy.2. 2. the plan designer will encounter design situations ranging from new highway construction. While these types of projects differ greatly in their scope and complexity. 000 to 20. Complaints will be significant if ESC is not maintained and cars travel through mud covered roads. In a residential plan. or dust becomes a nuisance. utility relocation is usually addressed within the scope of the contract right of way.2. Other methods of soil stabilization must often be used when organic materials such as vegetation cannot be used. The public needs to be assured that reasonable measures are taken to avoid these problems. utility construction is not a large contributor. A stabilized construction entrance at all points of ingress and egress is important and will need constant attention to maintenance due to frequent 6 2. Because SS is often located in or near wetlands. roadways are flooded. DNREC has developed a General Permit for minor utility installation. Smaller utility projects often include servicing residential development with water. Typically.will be necessary to ensure that the use of inlet protection devices does not pose a flooding hazard to existing travel lanes. This is due to the fact that utility construction is generally performed in narrow rights of way. it may help to think of the convenience store site. 2. 6 A final word to designers for DOT projects. perimeter controls such as silt fence may be employed. with most of the activity contained in trench work. electric.000 square foot building footprint. 6 Highway construction is more dynamic than most other types of construction. and cable. These small sites may range from 5. and stream crossings. The designer must plan for waterway construction permits as well as prepare detailed methods for temporary stream diversions. flood plains and along stream corridors. the ESC plan requirements must be addressed. For all other private utility relocation and installation however. Areas that are disturbed are not usually left inactive for long periods of time. In most instances. retail outlet or industrial park pad site. 2. As a gross source of sediment.2. sewer. Often it will be necessary for streams to be crossed by utility construction. and need to be recognized. For those utility projects that do not fit the criteria of the General Permit. gas.7 UTILITY CONSTRUCTION During DelDOT contracted projects. associated parking and landscaped areas. Several rolls of erosion control matting should be on site for the immediate stabilization of small utility installations. and disturb more than 5. fast food. Large utility projects such as sanitary sewer (SS) main installation pose the greatest risk for ESC problems during construction. especially with street construction and stabilizing adjacent right of way areas. the installation of separate utilities can disrupt the overall sequence of construction. Unlike private residential or commercial construction. gas station. de-watering operations. especially the restoration and stabilization of disturbed areas. the installation of utilities must be coordinated.11 12/03 . the visual access to many of these highway projects for the public is high. the construction must be undertaken so that these resource areas are protected. While the trend is toward utilizing a common trench for several or more of these utilities.8 COMMERCIAL/INDUSTRIAL DEVELOPMENT – SMALL SCALE (LESS THAN 3 ACRES) When visualizing the Commercial/Industrial Development (CID) small scale. This makes temporary stabilization difficult in many cases. telephone.000 square feet. a bulk grading plan will not be necessary. Roadway areas that are to remain inactive and free of vegetation usually require the application of a non-organic soil stabilization product. and ESC planned for. There are several unique aspects of utility work that do pose a challenge to the ESC plan designer. as the site controls for ESC may be designed for the entire construction sequence. a designed plan is necessary. These berms may be constructed from the topsoil stripped from the site. If only minor grading of the site is required. compacted by heavy equipment. office complexes. the inspection agency will want to ensure that Phase II is in full compliance with the plan.9 COMMERCIAL/INDUSTRIAL DEVELOPMENT – LARGE SCALE (GREATER THAN 3 ACRES) Obviously. and bulk grading has begun to take place. transporting and filling of land. Once stabilized.2. this site should require simple routine maintenance until the remainder of the site area is final graded for parking and landscaping. One important note. grubbing and grading stages of construction. a small scale CID can be easily managed for proper ESC. the building footprint area or pad site is excavated first. If not. Consider the three phases outlined below.traffic from trucks hauling structural building materials. as CID grows larger. There is a way through proper sequencing.Clearing. While the building area is being constructed. it is important to define the clearing. the stormdrain system is installed. Depending on the permanent stormwater design of the site. Some small commercial sites relay on infiltration. Generally.A second area of the site has been cleared of trees.The plan review and inspection agency may allow the developer to begin clearing trees in Phase III without grading taking place. or installed prematurely and allowed to become clogged with sediment. Used as berms around the perimeter. the sequence may be such that grading and base course stone could occur early in the construction. Phase I . which is often a problem on a small site. temporary stabilization would be done initially. 6 Phase III . All areas outside of the building area have been temporarily stabilized. a temporary sediment trap may be employed. This may depend on whether this Phase drains to a separate point. Shopping centers. and inlet protection if appropriate is constructed. On a wooded site.12 . This would also reduce the amount of bare soil exposure. 2. Phase II . The developer is now allowed to begin another phase of construction. If the remainder of the site requires extensive grading later. A temporary sediment trap is in place. 12/03 2 . the topsoil does not take up room as a stockpile. Before any stumps are removed. a stormwater pond may be available to utilize as a temporary sediment basin. grading. The ESC portion of the plan has to be developed to compliment the post-development stormwater management strategy. industrial parks all fit the heading of CID on a large scale. with rough grading taking place around the remainder of the site. The Delaware Sediment and Stormwater Regulations define land disturbing activity as a land change … including but not limited to clearing. The designer can enable this process to become more manageable by introducing phasing into the site planning process even when the site is less than 20 acres. The function of these facilities is often compromised when they are utilized for sediment control. the strategy of the ESC plan will grow increasingly complex. In discussing phasing. and grading takes place. Diversion berms are in place directing runoff to the traps. Properly designed. filtration or bioretention for their permanent stormwater management. to develop a portion or phase of a site while simultaneously clearing and grading another phase. excavating. Perimeter controls are established. cutting down or clearing trees is a land disturbing activity. and rough grading have been completed. The stormdrain system is installed to the stormwater management pond functioning as a sediment basin. with perimeter berms directing the flow of sediment laden water to the traps. There are typically very few areas of these sites that will remain undisturbed. runoff.10 RESIDENTIAL DEVELOPMENT . stormwater practices contaminated. it may be necessary to place the excavated material at a central location. The ESC strategies are very different during the bulk grading and infrastructure development stages. If proper on-lot controls are not maintained. A second plan would be necessary when rough grading nears completion. culvert pipes filled with sediment.7 of the Handbook. it may be necessary to develop two ESC plans. makes it difficult to manage drainage. Two Staged Plans . rarely exceed 80% removal rates for sediment. road swales are destroyed. these are rural developments that involve the lots being sold individually over an extended period of time. A properly designed ESC for a large scale CID. possibly in another Phase. making ESC critical for implementation by the homebuilder. soil erosion and the resulting sediment load.13 12/03 . The lot grading and home construction would normally be handled entirely through the Standard Plan for Minor Land Disturbing Activity. 2. The developer has usually fulfilled their responsibility once the road and infrastructure has been completed. and serious erosion problems develop that will be left unrepaired. the distinction will be different than with commercial development.2. In some cases extreme changes in grading are necessary to ensure a relatively flat site.11 RESIDENTIAL DEVELOPMENT – LARGE SCALE (MASS EARTHWORK) To differentiate between large scale and small scale residential development. will typically involve several phases. Individual lots being constructed by many different builders without the coordination of a site superintendent.) 2. the phasing is clearly the key to managing the ESC activity. even within a phase of construction. It is essential for the ESC designer to remember that sediment control facilities. the ESC plan will rely on temporary berms. Phasing also works well if the phases are broken into separate drainage areas. possibly more than one ESC stage and utilize many of the practices in this handbook.2. Typically the stormwater management facility is completed. However.While phasing is an important tool in managing ESC activities. 1. Residential development will be considered large scale when the entire site will 6 2. During the bulk grading of a large site. 2. buildings. roads. and now drain to the same traps and basins through an improved stormwater conveyance system. except those areas that are protected. This type of residential development is difficult to manage for two reasons. The first plan would be developed for the bulk grading activity. or drainage areas may be divided to outlet in different directions. Typically.SMALL SCALE (ROADS ONLY OR SINGLE LOT) This type of residential construction involves a developer preparing an ESC plan for the roads and infrastructure. even when designed and constructed properly. swales and diversions to convey sediment-laden water to traps and basins. Since the stormwater or drainage collection system is not installed at this time. and parking areas are under construction. In other cases multiple drainage areas will be graded to drain to one control point. Financial obligations are completed and guarantees are released.A well designed ESC plan for large scale CID will reflect that the site will likely be mass or bulk graded. (NOTE: A typical ESC plan for single family home construction is found in Section 3. If a sediment basin is to be constructed in Phase I. the plan needs to consider some flexibility among phases. and drainage established.14 . This installation will sometimes interfere with previously constructed silt fence and other E&S controls. the sediment basins and traps. The site planning and building permit-issuing authority typically coordinates phasing of residential development. There are three stages to a large-scale residential development (LSRD). and drainage systems. The amount of bulk grading will depend on the earthwork balance from the site. it is important for the ESC plans to consider the necessary integration of the phases. involves the home construction. electric. or earth brought in if the road area is in fill. the bulk grading stage will be easier to manage. If located underground. It is unusual for a developer to provide infrastructure for multi-phases and provide the needed financial guarantees until income is generated through lot or home sales. the building lots and homes are constructed by different subcontractors that may not have the heavy equipment necessary to complete the necessary maintenance. bulk or mass grading would require a separate ESC plan for that stage. Although the site should be inspected during the entire construction process. Because of this. 6 Home Construction Phase . the major infrastructure stage begins.The final stage in the LSRD construction. and telephone are generally installed in a common trench along the road right-of way. the sheet flow occurring during the bulk grading stage is now concentrated. the road areas will be “roughed” or “boxed” out if the roadway is in cut. but multi-phased projects may take years to complete. and the management of stormwater during construction. As earthwork progresses. Generally. there is the added consideration for the planner. phased development is driven by the economics of home sales.be mass or bulk graded. Site Improvements Stage . The contributing drainage area including lot areas must be stabilized before the permanent infiltration/filtration facilities or systems are put on-line. that home lots will eventually become part of the plan. Often. If cuts and fills are balanced. It is still early in the construction phase to activate any of the permanent infiltration/ filtration facilities or systems that may have been installed. and the rest of the site. The ESC planner will need to realize that the construction of the roadway and drainage system will alter the interception of stormwater runoff. 6 Bulk Grading 6 Site Improvements 6 Home Construction Each stage is unique with respect to erosion and sediment control. Once this stage is completed. the utilities are installed before home construction begins. and before the road right of way 12/03 2 . major utilities such as sewer and water.The next stage in the LSRD involves the installation of roads. Putting the base course of stone on the road as soon as possible will also reduce erosion potential. residential construction is not only a dynamic process. The lot areas of the site that have been previously stabilized will be disturbed during the construction of the homes. As basins and traps are constructed. drop structures.As with large scale CID. and possibly turf reinforcement in swales and ditches is now necessary. Energy dissipation with check dams. temporary stabilization may take place on the lot areas and many of the roadway swales and drainage channels are ready to receive the permanent stabilization treatment. Bulk Grading Stage . it is crucial to ensure that any major work is performed before the site contractor leaves. As the roadway cuts and fills are completed. For this reason. After the infrastructure is installed and before the site contractor leaves the site. and in many cases. the stormdrain system must be protected to prevent soil from migrating to the infiltration system. Ideally. should be checked to determine if maintenance is needed. typically. Minor utility installation such as cable. and the siting of these facilities needs to consider their long-term use. Here are several. a number of references have been made regarding specific types of ESC plans. recent homeowners who are trying to establish yards and landscaping should not be subject to sediment runoff from adjacent homes under construction. it seems unnecessary to keep sediment on-site when the development is served by a sediment basin. (NOTE: A typical ESC plan for single family home construction is found in Section 3. There are many valid reasons though. 3.12 COMPONENTS OF A DESIGNED PLAN FOR EROSION AND SEDIMENT CONTROL (ESC) Throughout this Section.areas are stabilized. You are communicating with a site superintendent who is responsible for the entire operation. 1. the installation priority may be tied to the number of building permits issued in a given development phase. 2. check dams and any other central site controls until the contributing drainage area is stabilized. or a homebuilder that purchases some or all of the lots. Often however.and Post-Development Grading and Contours Perimeter Controls 6 2. The construction of the residential home may be done by the land developer. for the homebuilder to maintain on-lot controls. This will be easier and less costly to accomplish if the ESC plan for the single home construction has been followed.15 12/03 . thereby allowing a certain percentage of sediment laden water to leave the site. This may necessitate the road right of way areas having to be stabilized twice.) 2.2. and it is up to the homebuilder to assume responsibility for maintaining an individual ESC plan for each home under construction. As homes in the development are completed. Generally it is easier to manage the ESC plan when the developer is the builder. the site contractor has left the project. The site developer will remain responsible to clean out the sediment basin. When utility installation requests are high however. maintain roads. Not each of these practices is necessary in all cases. ESC Schematic Plan Graphical Overview of ESC Plan Basic Site Features Legend Standard Symbols and Data for ESC Practices Land Development Plan Sheets Disturbed Areas / Limit of Disturbance / Areas of Preservation Land Grading Techniques Pre. however all residential homes under construction must comply with the conditions of the Standard Plan for Minor Land Distrubing Activity. On the surface.7 of the Handbook. The homebuilder will ultimately have to provide a final grade and permanent lot stabilization prior to receiving a certificate of occupancy. This last section outlines the components or parts of the ESC plan. The sediment basin serving the site does not function with 100% efficiency. 4. That goal can only be accomplished if each person carries out his or her responsibility in the land development process. Implementation requires that the following elements be accomplished during the land disturbing phase: Conduct a Pre-Construction Meeting “Dry run” of the entire project prior to any land disturbance Ensure the Contractor will be able to implement the plan as designed Resolve conflicts in the plan before they become a problem in the field Define Responsibilites of All Parties Plan Designer Owner/Developer Review Agency. Contractor.) Conveyance System Temporary and Permanent Stabilization Areas Legend Details and Specifications Written Information Approvals Owner/Developer Certification(s) Location and Vicinity Map General and Special Notes Construction Instructions Vegetative Notes Sequence of Construction 2. Inspector Conduct Regular Site Inspections Weekly and after each significant rain event Maintain ESC Practices Restore any damaged or degraded practices in a timely manner 6 Protection of our soil and water resources requires the preparation of an adequate plan and successful implementation of that plan.16 . 12/03 2 .Land Development Plan Sheets (cont.2.13 IMPLEMENTATION OF THE EROSION AND SEDIMENT CONTROL PLAN Even the best ESC plan will not accomplish the desired result if it is not successfully implemented. Appendix 2-A Standard Symbols 6 2A .1 12/03 . 2 .This page left intentionally blank. 6 12/03 2A . 1 Sediment Trapping Practices SBB 3.6 Culvert inlet protection CIP 6 2A .1.1 Standard Silt Fence 3.3 12/03 .1.2 Inlet Protection .1.1.1 Straw Bale Barrier 3.5.PRACTICE SYMBOL 3.2.5.Type 2 IP-2 3.3 Sediment Traps 3.3 Riprap Outlet Sediment Trap RST TSB 3.2.1.1.3.5 Storm Drain Inlet Protection 3.3 Super Silt Fence SSF 3.3.1.4 Temporary Sediment Basin 3.1 Inlet Protection .2.2 Reinforced Silt Fence RSF 3.1.3.1.1.1.1 Pipe Outlet Sediment Trap PST 3.2 Silt Fence SF 3.1.1.1.2 Stone Outlet Sediment Trap SST 3.Type 1 IP-1 3. channel .P t 3.3.2 Geotextile Dewatering Bag GB 3.Type 1 PP-1 3.Type 1 DWB-1 3.4 .1 Portable Sediment Tank ST 3.Type 2 DWB-2 TS .2.2.4 Dewatering Basin 3.2.1 Veg.1.3 Vegetated Channel 6 12/03 2A .4.1 Dewatering Basin .1 Pumping Pit .1 Temporary Swale t 3.3.2.2.2 Dewatering Practices 3.2 Pumping Pit 3.2.(A/B)(1-4) t 3.2 Dewatering Basin .2.3.3.2 Temporary Earth Berm TB .2.(A/B)(1-4) 3.3 Water Control Practices 3.3.2.2.2 Pumping Pit .PRACTICE SYMBOL 3.Type 2 PP-2 3.2.3 Dewatering Device 3.2 Pipe Dewatering Device PDD 3.Triang.1.3.1 Skimmer Dewatering Device SDD 3.2 Veg.4.2.2. VC.1 Portable Dewatering Practices 3. Channel .T t 3.2./Trap.3.3.Parabolic VC.3. 10.6 Stone Check Dam t t (VC/LC).) t 3.2 Gabion Mattress Chute GMC t 3.(P/T) D 3.PRACTICE SYMBOL (VC/LC)-(P/T) + PD 3.3.9.T t 3.8 Pipe Slope Drain PSD .Triang.) LC.9 Chute 3.3. LC.3 Water Control Practices (cont.11 Riprap Stilling basin RSB 6 2A .3.1 Riprap Chute RRC t 3.3./Trap.3.3.Parabolic t 3.2 ROP .3.4.Type 2 ROP-2 3.4 Lined Channel SCD 3.3.P 3.9.10 Riprap Outlet Protection 3.3.3 Channel Pipe Drain t 3.2 Lined Channel .7 Subsurface Drain N/A 3.10.1 ROP .3.1 Lined Channel .5 12/03 .3.4 Channel Stone Drain VC-(P/T) + SD t 3.3.4.3.Type 1 ROP-1 3.3.3.3.3.5 Diversion 3.3.(Dia. 6.3.4.5 Mulching N/A 3.1 Slope Treatment .1 Topsoiling 3.4.4 Soil Stabilization Practices N/A 3.PRACTICE SYMBOL 3.Slope SM-S 3.4.3 Vegetative Stabilization 3.4.8 Dust Control N/A 6 12/03 2A .4.2.1 Soil Testing N/A 3.7 Stabilized Construction Entrance SCE 3.4.3.6 .4.4.3. Matting -Channel SM-C 3.2 Slope Treatment .4.4.2 Slope Treatment 3.2 Stab.6.4.6 Stabilization Matting 3.3 Permanent Stabilization N/A 3.4.2 Temporary Stabilization N/A 3.2.4.Grooving ST-G 3.4 Streambank & Shoreline Stabilization N/A 3.4 Sodding N/A 3.1 Stab.4.3 Slope Treatment .4.3.2.4.Serrating ST-S 3.Benching ST-B 3.4. Matting . 7 Misc.1.6 Pollution Prevention Practices 3.) 3.5.7.2.Culvert TC-C 3.1 Construction Site Pollution Prevention N/A 3.1 Temporary Crossing 3.5.3 Turbidity Curtain 3./Alt.5.2 Cofferdam Stream Diversion CD 3.1 Temporary Crossing .5.1.1.2 Stream Diversion 3.2.Timber Mat TC-M 3. Practices N/A 3.2 Temp.5.3 Temporary Crossing .5.1 ESC for Minor Land Development 3.5.5.1.2.1 Utility Crossing Diversion Pipe DP 3.5 Waterway Construction Practices 3.Brdg. Crossing .(1/2/3)(Std. TC-B 3.Ford TC-F 3.5.7 12/03 .7.3 Stream Diversion Channel SD TC.5.2 Tree Protection TP 6 2A .4 Temporary Crossing .6.PRACTICE SYMBOL 3. This page left intentionally blank.8 . 6 12/03 2A . 6 3. 3. Straw bale barriers are to be used for no more than three (3) months. steepness refers to the steepest slope section contributing runoff to the straw bale dike. Purpose: A bale barrier reduces runoff velocity and effects deposition of the transported sediment load.1 12/03 . 2. Design Criteria A design is not required.000 feet 750 feet 500 feet 250 feet 125 feet Where slope gradient changes through the drainage area. straw bale barriers shall not be used as a primary control practice.STANDARD AND SPECIFICATIONS FOR STRAW BALE BARRIER Definition: A temporary barrier of straw or similar material used to intercept sediment laden runoff from small drainage areas of disturbed soil.1 . 4. SLOPE SLOPE STEEPNESS SLOPE LENGTH (maximum) BARRIER LENGTH (maximum) 0% to 2% 2% to 10% 10% to 20% 20% to 33% 33% to 50% Greater than 50% Flatter than 50:1 50:1 to 10:1 10:1 to 5:1 5:1 to 3:1 3:1 to 2:1 Greater than 2:1 250 feet 125 feet 100 feet 75 feet 50 feet 25 feet 1. Where erosion would occur in the form of sheet erosion. As a secondary practice controlling local areas of minor disturbance and/or minor dewatering operations. Conditions Where Practice Applies: 1. Where length of slope to the straw bale barrier does not exceed these limits. All bales shall be placed on the contour with the binding string not in contact with the ground.1. In areas where there is no concentration of water in a channel or other drainageway above the barrier.000 feet 1. 6 12/03 3.1.2 .This page left intentionally blank.1 . SBB DE-ESC-3. 4" Section Flow Wrap ends upslope so as to contain runoff Straw bale (Typ.1 Sheet 1 of 2 12/03 Date: _________________ .) (2) Re-bar or 2"X2" wood stakes per bale Plan Source: Adapted from VA ESC Handbook Symbol: Detail No.) Compacted soil Wire or string binder oriented horizontally Flow Embed min.Standard Detail & Specifications Straw Bale Barrier Re-bar or 2"X2" wood stake (Typ.1. Place and stake straw bales Angle first stake toward previously laid bale 4" Flow Bale width 3. Bales shall be removed when the site has been permanently stabilized. Stakes shall be driven flush with the top of the bale. 4. DE-ESC-3. Wedge loose straw between bales 4. The first stake in each bale shall be driven toward the previously laid bale at an angle to force the bales together. Backfill and compact the excavated soil Construction Notes: 1. Source: Adapted from VA ESC Handbook Symbol: Detail No. Bales shall be placed at the toe of a slope or on the contour and in a row with ends tightly abutting the adjacent bales. and placed so the bindings are horizontal.Standard Detail & Specifications Straw Bale Barrier Construction D etail Detail 1.1 SBB Sheet 2 of 2 12/03 Date: _________________ . Excavate the trench 2. Inspections shall be frequent and repairs and replacements shall be made promptly as needed. 5. 2. Each bale shall be embedded in the soil a minimum of (4) inches. 3.1. Bales shall be securely anchored in place by either two stakes or re-bars driven through the bale. STANDARD AND SPECIFICATIONS FOR SILT FENCE Definition: A temporary barrier of geotextile fabric (filter cloth) used to intercept sediment laden runoff from small drainage areas of disturbed soil. All silt fence shall be placed as close to the contour as possible and the area below the fence must be undisturbed or stabilized. Erosion would occur in the form of sheet erosion.1. Soil conditions allow proper keying of the skirt (i. Fence Length Standard Reinforced Super Unltd / Unltd N/A N/A 125' / 1000' 250' / 2000' Unltd / Unltd 100' / 750' 150' /1000' 200' / 1500' 60' / 500' 80' / 750' 100' / 1000' 40' / 250' 70' / 350' 100' / 500' 20' / 125' 30' / 175' 50' / 250' Installation: Silt fence shall be installed in accordance with the appropriate detail. Slope Length / Max. The type of silt fence specified for each location on the plan shall meet the maximum slope length and maximum fence length requirements shown in the table below: Slope < 2% 2 .2 . 3. 6 3.1 6/05 ..10% 10 . Seams shall be overlapped. Conditions Where Practice Applies: 1. no large stones or bedrock near the surface). Maximum allowable slope length and fence length will not be exceeded.20% 20 . There is no concentration of water flowing to the barrier.50% > 50% Steepness < 50:1 50:1 to 10:1 10:1 to 5:1 5:1 to 3:1 3:1 to 2:1 > 2:1 Max.e. 2.33% 33 . 4. folded and stapled to provide a continuous section. Design Criteria Design computations are not required. Butt joints are not acceptable. Maximum period of use is limited by ultraviolet stability. Purpose: To temporarily pond sediment laden runoff and allow deposition to occur. 2 . 2. Attachment: The geotextile material shall be securely attached to the post with staples. 6 6/05 3. The use of a new material may be approved by the appropriate erosion and sediment control plan approval authority on a case-by-case basis. ties or other appropriate means. Other materials: Other materials used for specific types of silt fence installations are indicated on the appropriate detail. 3. Posts for super silt fence shall be standard chain link fence posts. it should still be inspected for possible wind damage. However. Steel posts shall be standard "T" or "U" section weighing not less than 1. 3. 4. Wood posts will be of sound quality hardwood with a minimum cross sectional area of 4.1. all silt fence installations shall include a reinforcement strip or other means of reinforcing the attachment of the geotextile material to the post to prevent wind damage. In addition. Statewide acceptability shall depend on infield and/or laboratory observations and evaluations. Fence Posts: The length shall be a minimum of 40 inches long. Silt Fence Fabric: The geotextile material shall meet the specifications contained in Appendix A-3. nails.00 pound per linear foot.0 square inches. Prefabricated Units: Prefabricated silt fence is acceptable provided all material specifications are met. Maintenance: Silt fence must be inspected on a regular basis. Accumulated sediment should be removed when it has reached 1/2 the exposed height of the fabric. such approval shall not constitute statewide acceptance.Specifications for Silt Fence Materials 1. Even though a rain event may not have occurred.2 . Repairs should be made immediately. each stake) Min.2. controlled slope Source: Adapted form MD Stds. 16" stake length driven into ground Section Flow Ends placed upslope to contain runoff 6' Max..) DATA Max.1. 8" vertically into ground Min. for ESC Plan Symbol: Detail No. 2" X 2" wooden post (Typ.Standard Detail & Specifications Silt Fence Min.1 Sheet 1 of 2 6/05 Date: _________________ . 40" stake length Reinforcing strip over geosynthetic fabric (typ. 24" stake length above ground Flow Embed fabric min. SF DE-ESC-3. & Specs. & Specs. plastic strip or other approved equivalent 4. DE-ESC-3. Maintenance shall be performed as needed and material removed when “bulges” develop in the silt fence. 2. Materials: 1. Reinforcing strip: Wooden lath. 3.1 SF Sheet 2 of 2 6/05 Date: _________________ . Prefabricated Unit: Geofab. Envirofence.2. Stakes: Steel (either T or U) or 2" x 2" hardwood 2. Geosynthetic fabric to be fastened securely to fence posts with wire ties or staples. or approved equivalent Source: Adapted from MD Stds. When two sections of filter cloth adjoin each other they shall be overlapped by six inches and folded.Standard Detail & Specifications Silt Fence Construction D etail Detail Posts Staple Section B Section A Method for joining continuous sections Staple Top Construction Notes: 1. for ESC Symbol: Detail No. Geosynthetic Fabric: Type GD-I 3.1. Cross-section Source: Symbol: Adapted from Transco.Standard Detail & Specifications Reinforced Silt Fence Min. Flow 8" Min. 40"post driven min. Inc. 8" into ground 16" min.. Flow Embed geosynthetic fabric min. Detail No. 40" post Welded wire fabric backing 3 1 Geotextile fabric 18" Min. 14 Ga. Max. Welded wire fabric backing (Min. Flow 1"x1"x12" Stake (as needed) Min. controlled slope Min.2 Sheet 1 of 2 6/05 Date: _________________ . RSF DE-ESC-3.2. 2" X 4" mesh) 24" Min.C. 6' O. 10 Ga. wire (as needed) Perspectiv erspectivee DATA Max.1. 16" into ground Max. 1. 3.Standard Detail & Specifications Reinforced Silt Fence Construction Notes: 1.2. 2" X 4" mesh opening Source: Symbol: Adapted from Transco. Maintenance shall be performed as needed and material removed when "bulges" develop in the silt fence. Inc. RSF DE-ESC-3. Geotextile Fabric: Type GD-I 3. they shall be overlapped by six inches and folded. Filter cloth to be fastened securely to woven wire fence with ties spaced every 24 inches at top and mid-section. Prefabricated Unit: Geofab. Posts: Steel either T or U or 2" x 2" hardwood 2. Envirofence. Detail No. Welded wire fabric to be fastened securely to the fence posts with wire ties or staples. Backing: Woven welded wire. Materials: 1. 4. or approved equivalent 4. 14 Ga.2 Sheet 2 of 2 6/05 Date: _________________ .. 2. When two sections of fabric adjoin each other. galvanized or aluminum posts Chain link fence with geotextile fabric 8" Min. SSF DE-ESC-3. Perspectiv erspectivee Post Chain link fencing Geotextile fabric 33" min. post and 2nd layer geotextile fabric 16" min.3 Sheet 1 of 2 12/03 Date: _________________ . for ESC Symbol: DATA Max. 33" Min. 36" Min. Flow 2-1/2" dia.Standard Detail & Specifications Super Silt Fence 10' Max. controlled slope Detail No.1. & Specs. 1st layer geotextile fabric Flow Embed fabric min.2. 8" into ground Section Source: Adapted from MD Stds. When two sections of geotextile fabric adjoin each other. substituting 42 inch fabric and 6 foot length posts. & Specs.Standard Detail & Specifications Super Silt Fence Construction Notes: 1. Maintenance shall be performed as needed and silt buildups removed when "bulges" develop in the silt fence. 4. they shall be overlapped by 6" and folded. Materials: 1. for ESC Symbol: Detail No. Geosynthetic Fabric: Type GD-I Source: Adapted from MD Stds.1. Chain link fence shall be fastened securely to the fence posts with wire ties or staples. 5. 6.2. 2. Geotextile fabric shall be fastened securely to the chain link fence with ties spaced every 24" at the top and mid section. The Del-DOT specification for a 6 foot fence shall be used.3 Sheet 2 of 2 12/03 Date: _________________ . Fencing: Fencing shall be 42 inches in height and constructed in accordance with the latest Delaware Department of Transportation (Del-DOT) Specifications for Chain Link Fencing (Section 728). 3. 2. The poles do not need to be set in concrete. SSF DE-ESC-3. Geotextile fabric shall be embedded a minimum of 8" into the ground. ........ and rights-of-way below the sediment trap from sedimentation.. 3...... See Additional Standard Riprap Outlet Sediment Trap .............. Locate traps to obtain maximum storage benefit from the terrain................... Drainage Area The drainage area for sediment traps shall be in accordance with the specific type of sediment trap used (see Additional Standard for each type). 2... 6 3....1..... for ease of cleanout and disposal of the trapped sediment... See Additional Standard Design Criteria If any of the design criteria presented here cannot be met.... Location Sediment traps shall be located so that they can be installed prior to grading or filling in the drainage area they are to protect... If any of the design criteria presented here cannot be met.3...... see Standard and Specifications for Temporary Sediment Basin........1 12/03 ............. properties. Purpose:To intercept sediment-laden runoff and trap the sediment in order to protect drainage ways.. Conditions Where Practice Applies: A sediment trap is usually installed in a drainageway or at points of discharge from a disturbed area. 1... See Additional Standard Stone Outlet Sediment Trap .......STANDARD AND SPECIFICATIONS FOR SEDIMENT TRAP Definition: A temporary sediment control device formed by excavation and/or embankment to intercept sediment-laden runoff a n d to retain the sediment..... see Standards and Specifications for Temporary Sediment Basin.. Traps must not be located any closer than 20 feet from a proposed building foundation if the trap is to function during building construction... TYPES OF SEDIMENT TRAPS There are three (3) specific types of sediment traps which vary according to their function..... location or drainage area........ Pipe Outlet Sediment Trap . Sediment traps should not be used to artificially break up a natural drainage area into smaller sections where a larger device (sediment basin) would be better suited...... etc.600 cubic feet per acre of drainage area.2 of the Handbook. Each trap shall be inspected after each runoff event. Wet pool storage will enhance performance and should be provided whenever practicable. but may not be used to fulfill the temporary storage requirement. Points of entry should be located so as to insure maximum travel distance of the incoming runoff to point of exit (the outlet) from the trap. Sediment shall be removed and the trap restored to the original dimensions when the sediment has accumulated to 1/2 of the design depth of the trap. Dewatering Methods The method of dewatering each trap shall be indicated on the plan.3 . Maintenance 1.4 x surface area (sq ft) x maximum depth (ft).1. Entrance of Runoff Into Trap Considerable care should be given to the major points of inflow into traps. 2. constructed and maintained in such a manner that sediment leaving the trap is minimized and that erosion at or below the outlet does not occur. In many cases the difference in elevation of the inflow and the bottom of the trap is considerable. The volume of a natural sediment trap may be approximated by the equation. thus creating potential for severe gullying and sediment generation. Embankments shall have a minimum four (4) foot wide top and side slopes of 2:1 or flatter. The volume of a constructed trap shall be calculated using standard mathematical procedures. berms. Diversions. Often a riprap chute at major points of inflow would eliminate gullying and sediment generation.Trap Size The volume of a sediment trap as measured at the elevation of the crest of the outlet shall be at least 3. The embankment shall be compacted by traversing with equipment while it is being constructed. shall be repaired immediately. Volume (cu ft) = 0. 6 12/03 3. Excavated portions of sediment traps shall have 1:1 or flatter slopes. grade stabilization structures or other water control devices shall be installed as necessary to insure direction of runoff and protect points of entry into the trap. 3. Trap Details for Erosion and Sediment Control Plans Each trap requires specific information to be provided on the plan. The Standard Detail and Specification indicates the data required for each type. Each trap should be identified on the plan and the appropriate data provided. into a watercourse. or into a storm drain system. Sediment removed from the trap shall be deposited in a protected area and in such a manner that it will not erode. Any damage to outlet structures. Excavation All excavation operations shall be carried out in such a manner that erosion and water pollution shall be minimal.2 . stabilized channel. Outlet The outlet shall be designed. Sediment traps must outlet onto stabilized (preferably undisturbed) ground. These methods shall be in accordance with the Standard and Specifications for the various dewatering practices included in Section 3. Embankment All embankments for sediment traps shall not exceed five (5) feet in height as measured at the low point of the original ground along the centerline of the embankment. Pipe outlet sediment traps may be interchangeable in the field with stone outlet or riprap sediment traps provided that these sediment traps are constructed in accordance with the detail and specifications for that trap. Sizes of Pipe Needed Pipe outlet sediment traps shall be limited to a five (5) acres maximum drainage area. The plate shall have 2. The riser shall have a base with sufficient weight to prevent flotation of the riser. Two approved bases are: (1) A concrete base 12" thick with the riser embedded 9" into the concrete base. In either case.Drainage Are (inches) (acres) 15" 18" 21" 24" 27" 1 2 3 4 5 6 3. or (2). each side of the square base measurement shall be the riser diameter plus 24 inches. The riser shall be wrapped with 1/2 to 1/4 inch hardware clothwire then wrapped with filter cloth at least six (6) inches above the highest hole and six (6) inches below the lowest hole. gravel.ADDITIONAL STANDARD AND SPECIFICATIONS FOR PIPE OUTLET SEDIMENT TRAP Design Criteria: Pipe Outlet Sediment Trap consists of a trap formed by an embankment or excavation.3. The top 2/3 of the riser shall be perforated with one (1) inch nominal diameter holes or slits spaced six (6) inches vertically and horizontally placed in the concave portion of the corrugated pipe. The outlet for the trap is through a perforated riser and a pipe through the embankment. or earth placed on it to prevent flotation. The outlet pipe and riser shall be made of corrugated metal. All pipe connections shall be watertight.1.5 feet of stone.1/4" minimum thickness steel plate attached to the riser by a continuous weld around the circumference of the riser to form a watertight connection. No holes or slits will be allowed within six (6) inches of the top of the horizontal barrel. The top of the embankment shall be at least 1 1/2 feet above the crest of the riser. Select pipe diameter from the following table: Minimum Sizes Barrel Diameter* (inches) 12" 15" 18" 21" 21" Riser Diameter Max. The top of the riser pipe shall not be covered with filter cloth.3 12/03 . 6 12/03 3.3 .This page left intentionally blank.1.4 . Anti-seep collar (Typ. 1 Temp.1.1 DE ESC Handbook PST Sheet 1 of 2 12/03 Date: _________________ . 2' projection 1 10 ' Min. Storage Fill Height: 5' Max.3.Standard Detail & Specifications Pipe Outlet Sediment Trap 4' Min. DE #57 stone 6" min. Riser D etail Detail Source: Symbol: DATA Drainage area (D.) Profile thru Pipe Outlet Trash protection Geosythetic fabric 1" dia.) Riprap outlet protection on geosynthetic fabric (R-4 min.A. 2 2 Wet Pool 14" Min.) Required storage (VS) Design dimensions (L x W x D) Riser diameter Pipe diameter Detail No. perforations.C. Riser base: 12" thick concrete or 1/4" steel plate Water-tight coupling (Typ.) Min. spaced 6" O. 1' Min. DE-ESC-3. 3. Removed sediment shall be deposited in a suitable area and in such a manner that it will not erode. The fill material for the embankment shall be free of roots or other woody vegetation as well as oversized stones. They shall be placed at the top and bottom of the cloth.5 feet of stone. gravel or tamped earth placed on it. but shall not be used to fulfill the temporary storage volume requirement.600 cubic feet per acre of drainage area. An approved dewatering device shall be considered an integral part of the trap. cut slopes 1:1 or flatter. Concrete bases shall be 12 inches thick with the riser embedded nine (9) inches. 14. Dewatering operations shall be conducted in accordance with any and all regulatory requirements. All pipe connections shall be watertight. The structure shall be inspected after each rain and repairs made as needed. Where ends of filter cloth come together. Fill material around the pipe spillway shall be hand compacted in four (4) inch layers. 7. 9. The riser shall be anchored with either a concrete base or steel plate base to prevent flotation. or other objectionable material. Disturbed areas shall be stabilized in accordance with the Standards and Specifications for Vegetative Stabilization contained in this Handbook. The area under embankment shall be cleared. they shall be overlapped. 11. Construction operations shall be carried out in such a manner that erosion and water pollution are minimized.Standard Detail & Specifications Pipe Outlet Sediment Trap Construction Notes 1.1. folded and stapled to prevent bypass. 5. The structure shall be removed and area stabilized when the drainage area has been properly stabilized. The filter cloth shall extend six (6) inches above the highest hole and six (6) inches below the lowest hole. Straps or connecting bands shall be used to hold the filter cloth and wire fabric in place. 12. 6. The pool area shall be cleared. No holes will be allowed within six (6) inches of the horizontal barrel. 10. The plate shall have 2. PST DE-ESC-3. Steel plate bases will be 1/4 inch minimum thickness attached to the riser by a continuous weld around the bottom to form a watertight connection. The embankment shall be compacted by traversing with equipment while it is being constructed. Sediment shall be removed and trap restored to its original dimensions when the sediment has accumulated to 1/2 the design depth of the trap. MAXIMUM DRAINAGE AREA: 5 ACRES Source: DE ESC Handbook Symbol: Detail No. Wet pool storage should be provided whenever practicable. The riser shall be wrapped with filter cloth (having an equivalent sieve size of 40-80). A minimum of two (2) feet of hand-compacted backfill shall be placed over the pipe spillway before crossing it with construction equipment. 15. 8. All fill slopes shall be 2:1 or flatter.1 Sheet 2 of 2 12/03 Date: _________________ . organic material. rocks. 2. 13. The top 2/3 of the riser shall be perforated with one (1) inch diameter hole or slit spaced six (6) inches vertically and horizontally and placed in the concave portion of pipe. grubbed and stripped of any vegetation and root mat.3. 4. Volume of temporary storage shall be 3. 1. The temporary storage volume provided is determined by computing the volume of storage available behind the outlet structure up to the elevation of the crest of the stone outlet.600 cubic feet of required storage for each acre of drainage area over and above any storage provided as a wet pool. 2. The minimum length (feet) of the outlet shall be equal to four (4) times the drainage area (acres). The outlet crest (top of stone in weir section) shall be level. a layer of filter cloth should be embedded one (1) foot back into the upstream face of the outlet stone or a one (1) foot thick layer of DE #3 aggregate shall be placed on the upstream face of the outlet. The temporary storage for this trap shall be computed using 3.ADDITIONAL STANDARD AND SPECIFICATIONS FOR STONE OUTLET SEDIMENT TRAP Design Criteria Stone Outlet Sediment Trap consists of a trap formed by an embankment or excavation. 5. The use of the Stone Outlet Sediment Trap is the preferred sediment control device when traps are used.1.3 . MAXIMUM DRAINAGE AREA: 5 ACRES 6 3.5 6/05 . Stone outlet sediment traps shall be limited to a five (5) acre maximum drainage area. 4. Stone Outlet Sediment Traps may be interchangeable in the field with pipe or riprap outlet sediment traps provided they are constructed in accordance with the standard and specifications for those traps. Stone used in the outlet shall be small riprap (R4). The elevation of the top of any berm directing water to a riprap outlet sediment trap shall equal or exceed the minimum elevation of the embankment along the entire length of this trap. The outlet of this trap is over a stone section placed on level ground. 3. at least one (1) foot below top of embankment and no more than one (1) foot above ground beneath the outlet. The maximum height of embankment shall not exceed four (4) feet. Additional wet pool storage can be provided by excavating below the elevation required to fulfill the temporary storage volume. To provide a more efficient trapping effect. This page left intentionally blank. 6 6/05 3.6 .1.3 . Temp. Top of embankment Lw = 4 x D.) Required storage (VS) Design dimensions (L x W x D) Embankment height (H) Weir length (Lw) Riprap apron (R-4) A Perspectiv erspectivee DE #3 stone (1' thickness) 1 2 4' min. 3' max. 2 1 H = 4' max.3. storage Geosynthetic fabric R-4 riprap Excavate below this elevation for additional wet pool storage 5' min.A. 1' min.1. 2 Flow 1 1' min. & Specs. apron Section A-A 1' min.A. DE-ESC-3. grnd Section B-B Source: Adapted from MD Stds. for ESC Symbol: Detail No.2 SST Sheet 1 of 2 6/05 Date: _________________ . Ex.Standard Detail & Specifications Stone Outlet Sediment Trap Flow Compacted earth embankment B Excavated area A DE #3 stone B DATA Drainage area (D. Construction operations shall be carried out in such a manner that erosion and water pollution are minimized.2 SST Sheet 2 of 2 6/05 Date: _________________ . Sediment shall be removed and trap restored to its original dimensions when the sediment has accumulated to 1/2 the design depth of the trap. The volume of sediment storage shall be 3600 cubic feet per acre of drainage area in addition to any storage provided in the form of a permanent wet pool. The pool area shall be cleared. 6. grubbed and stripped of any vegetation and root mat. The fill material for the embankment shall be free of roots and other woody vegetation as well as over-sized stones. 5. MAXIMUM DRAINAGE AREA: 5 ACRES Source: Adapted from MD Stds. The plan shall include an approved means of dewatering the wet pool for necessary maintenance ar removal. 7. 4. The structure shall only be removed when the contributing drainage area has been properly stabilized.Standard Detail & Specifications Stone Outlet Sediment Trap Construction Notes: 1. The area under embankment shall be cleared. The stone used in the outlet shall be small riprap (R-4) along with a 1' thickness of DE #3 aggregate placed on the up-grade side on the small riprap or embedded filter cloth in the riprap. for ESC Symbol: Detail No. 3. organic material or other objectionable material. cut slopes 1:1 or flatter. Disturbed areas shall be stabilized in accordance with the Standards and Specifications for Vegetative Stabilization contained in this Handbook. rocks. Dewatering operations shall be conducted in accordance with any and all regulatory requirements. The embankment shall be compacted by traversing with equipment while it is being constructed. 9. OPTIONAL: A one foot layer of DE #3 stone may be placed on the upstream side of the riprap in place of the embedded filter cloth. 10. 2. 11.1.3. DE-ESC-3. All fill slopes shall be 2:1 or flatter. The structure shall be inspected after each rain and repairs made as needed. & Specs. 8. An approved dewatering device shall be considered an integral part of the trap. The riprap outlet sediment trap may be used for drainage areas of up to a maximum of 15 acres. 2. The elevation of the top of any dike directing water to a riprap outlet sediment trap shall equal or exceed the minimum elevation of the embankment along the entire length of this trap.1. 1. The storage needs for this trap shall be computed using 3. 4. Additional wet pool storage can be provided by excavating below the elevation required to fulfill the temporary storage volume.3. The total drainage area shall not exceed 15 acres. The temporary storage volume provided is determined by computing the volume of storage available behind the outlet structure up to the elevation of the crest of the riprap outlet channel. 3. This outlet channel shall discharge onto a stabilized area or to a stable watercourse. 6 3.600 cubic feet of required storage for each acre of drainage area in addition to any storage provided as a wet pool.ADDITIONAL STANDARD AND SPECIFICATIONS FOR RIPRAP OUTLET SEDIMENT TRAP Design Criteria Riprap Outlet Sediment Trap consists of a trap formed by an excavation and embankment. The maximum height of embankment shall not exceed four (4) feet. The outlet for this trap shall be through a partially excavated channel lined with riprap.7 6/05 . 0 2.0 10.0 14.0 16.Riprap Outlet Sediment Trap .5 1.Design Guidelines Contributing Drainage Area (Acres) Depth of Channel (a) (Feet) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1.0 2.0 16.0 10.0 12.0 2.5 1.0 .8 Length of Weir (b) (Feet) 4.5 1.0 2.1.0 10.0 2.0 14.3 .5 1.0 6.5 2.0 12.0 18.0 16.0 14.5 1.0 6 6/05 3.5 1.0 5.0 2.0 2. 1 2 10' Min. Thickness = 14") Geosynthetic fabric Cross-section of Outlet Source: Adapted from MD Stds. H (4' max. RST DE-ESC-3.3 Sheet 1 of 2 6/05 Date: _________________ .) a 14" Temp. & Specs. grnd a 2 Rip-rap (R-4.A.) Required storage (VS) Design dimensions (L x W x D) Embankment height (H) Channel depth (a) Weir length (b) Flared apron (end width = 1.5 x b) Perspectiv erspectivee 4' Min. storage Excavate below this elevation for additional wet pool storage Profile thru Outlet Top of compacted embankment min. 1' above top of stone lining b 1 Ex.3. for ESC Symbol: Detail No.Standard Detail & Specifications Riprap Outlet Sediment Trap Compacted embankment Excavated area Flow DATA Drainage area (D.1. measured at centerline of the embankment. organic material or other objectionable material. The fill material for the embankment shall be free of roots or other woody vegetation as well as over-sized stones. Fabric shall be embedded at least six (6) inches into existing ground at entrance of outlet channel. 10. The embankment shall be compacted by traversing with equipment while it is being constructed.1. 4.3. cut slopes 1:1 or flatter. Construction operations shall be carried out in such a manner that erosion and water pollution are minimized. Removed sediment shall be deposited in a suitable area and in such a manner that it will not erode. The pool area shall be cleared. Dewatering operations shall be conducted in accordance with any and all regulatory requirements. The area under embankment shall be cleared. Maximum height of embankment shall be four (4) feet. Sections of fabric must overlap at least one (1) foot with section nearest the entrance placed on top. DE-ESC-3. 8. 12. MAXIMUM DRAINAGE AREA: 15 ACRES Source: Adapted from MD Stds. for ESC Symbol: Detail No. Disturbed areas shall be stabilized in accordance with the Standards and Specifications for vegetative Stabilization contained in this Handbook. Elevation of the top of any dike directing water into trap must equal or exceed the height of embankment. The structure shall be inspected after each rain and repaired as needed. 9. rocks. Storage area provided shall be figured by computing the volume available behind the outlet channel up to the elevation of the crest of the outlet weir channel. & Specs. grubbed and stripped of any vegetation and root mat. An approved dewatering device shall be considered an integral part of the trap. Filter cloth shall be placed over the bottom and sides of the outlet channel prior to placement of stone. 3.Standard Detail & Specifications Riprap Outlet Sediment Trap Construction Notes: 1. 11. The structure shall be removed and the area stabilized when the contributing drainage area has been properly stabilized. 7.3 RST Sheet 2 of 2 6/05 Date: _________________ . 2. Stone used in the outlet shall be R-4 riprap with a thickness of 14". Sediment shall be removed and trap restored to its original dimensions when the sediment has accumulated to 1/2 the design depth of the trap. All fill slopes shall be 2:1 or flatter. 5. 6. The total volume of permanent sediment basins shall equal or exceed the capacity requirements for temporary basins contained herein. Permanent (to function more than 36 months) sediment basins or structures that temporarily function as a sediment basin but are intended for use as a permanent stormwater management facility shall be classified as permanent structures and shall conform to criteria appropriate for permanent structures. properties.STANDARD AND SPECIFICATIONS FOR TEMPORARY SEDIMENT BASIN Definition: A temporary barrier or dam constructed across a drainageway or at other suitable locations to intercept sediment-laden runoff and to trap and retain the sediment. 378 for ponds. 2. Failure of the structure would not result in loss of life. The basin is to be removed within 36 months after the beginning of construction of the basin. These structures shall be designed and constructed to conform to State criteria. damage to homes or buildings.S.1. local requirements.A. and rights-of-way below the sediment basin.4 .D. Purpose: The purpose of a sediment basin is to intercept sediment-laden runoff and reduce the amount of sediment leaving the disturbed area in order to protect drainageways. whichever is more restrictive. The drainage area does not exceed 100 acres. 6 3. and/or U. 3. Natural Resource Conservation Service Standards and Specifications No.1 6/05 . Scope: This standard applies to the installation of temporary sediment basins on sites where: 1. or interruption of use or service of public roads or utilities. erosion. Compliance with Laws and Regulations Design and construction shall comply with state and local laws. sediment basins must meet the following minimum criteria: Max. acres Max.600 cubic feet per acre of drainage area. This 3. but may not be used to fulfill the temporary storage volume requiement. The following discussion outlines additional criteria to be considered in the design process.4 . The data for these standard designs are shown in Figure 3. as measured from the bottom of the base to the elevation of the crest of the principal spillway shall be at least 3. 6 6/05 3. Min.Criteria for Temporary Sediment Basins For the purpose of this standard.2 .4a for drainage areas less than 10 acres and in Figure 3.1.1. rules and regulations.Embankment Top Width. It should be located to minimize interference with construction activities and construction of utilities. Embankment Side Slopes Anti-Seep Collar Req'd 100 15 10 2:1 Inside 3:1 Outside Yes * Height is measured from the low point of original ground along the centerline of dam to the top of the dam. sediment basins should be located so that storm drains may outfall or be diverted into the basin.1.600 cubic feet is equivalent to 1. Conditions Where Practice Applies: A sediment basin is appropriate where physical site conditions or land ownership restrictions preclude the installation of other erosion control measures to adequately control runoff. Size of the Basin The volume of the sediment basin.4b for drainage areas from 10 to 20 acres. Ft. Design Criteria for Temporary Sediment Basins: Standard designs have been established for temporary sediment basins having drainage areas less than 20 acres. ordinances. Whenever possible.Height* of Dam. Additional storage in the form of a permanent wet pool shall be provided whenever practicable. A worksheet has been provided based on the recommended design procedure (see Figure 3.Drainage Area. Location The sediment basin should be located to obtain the maximum storage benefits from the terrain and for ease of cleanout of the trapped sediment. The basin shall be maintained until the disturbed area is protected against erosion by permanent stabilization. and sedimentation.4c). It may be used below construction operations which expose critical areas to soil erosion.1. Basins which have drainage areas greater than 20 acres or which have special circumstances which preclude the use of a standard design shall have a site specific design. Ft.0 inch of sediment per acre of drainage area. 1. For those basins with no emergency spillway. where length is the distance between the inlet and outlet. leaks. The combined capacities of the principal and emergency spillway shall be sufficient to pass the peak rate of runoff from a 10-year frequency. 24-hour NRCS Type II rainfall event or a higher frequency corresponding to the hazard involved. Special situations which warrant a different methodology require approval from the Department. 6 3. Shape of the Basin It is recommended that the designer of a sediment basin strive to incorporate the following features: 6 Length to width ratio greater than 2:1.2 cfs per acre of drainage area when the water surface is at the emergency spillway crest elevation. In no case shall the sediment level be permitted to build up higher than one foot below the principal spillway crest. The minimum size of the barrel shall be 8 inches in diameter.A spillway consisting of a vertical pipe or box type riser joined (watertight connection) to a pipe (barrel) which shall extend through the embankment and outlet beyond the downstream toe of the fill. the principal spillway shall have the capacity to handle the peak flow from a ten year frequency rainfall event. Runoff computations shall be based upon the worst soilcover conditions expected to prevail in the contributing drainage area during the anticipated effective life of the structure. A procedure for the design of these structures is discussed later in this standard and specification.800 cubic feet per acre of drainage area (50 percent full). function can sometimes be improved by installing baffles in the basin pool area. In cases where site conditions prevent the use of the recommended shape.4f for principal spillway sizes and capacities.The riser and all pipe connections shall be completely watertight except for the inlet opening at the top or a dewatering opening and shall not have any other holes.Sediment basins shall be cleaned out when the volume remaining as described above is reduced by sedimentation to 1. b. cleanout shall be performed to restore the original design volume to the sediment basin. rips or perforations in it. 3.When used in combination with an emergency spillway. construction and inspection.4d.4e. The elevation of the maximum allowable sediment level shall be determined and shall be stated in the design data as a distance below the top of the riser and be clearly marked on the riser. The minimum capacity of the principal spillway shall be 0. a. The basin dimensions necessary to obtain the required basin volume as stated above shall be clearly shown on the plans to facilitate plan review. Spillway Design Peak rates of runoff values used in spillway design shall be based on USDA-NRCS methodology as outlined in TR 55 Urban Hydrology and/or TR 20 Project Formulation . Crest elevation . and 3. 1.1.1. 6 A wedge shape with the inlet located at the narrow end. the crest elevation of the riser shall be a minimum one foot below the elevation of the control section of the emergency spillway. At this elevation.3 6/05 .Hydrology. See Figures 3. Watertight riser and barrel assembly .4 . Principal spillway .1. each side of the square base shall be twice the riser diameter. Individual dewatering methods may be dictated by the intended use of the basin.An anti-vortex device and trash rack shall be securely installed on top of the riser and shall be the concentric type as shown on Sheet 3 of the Standard Detail and Specification for Temporary Sediment Basin. Dewatering the sediment is not required but some local ordinances may require some methods to dewater the basin and facilitate the cleanout process. The minimum factor of safety shall be 1. sediment. For details on these methods of dewatering. i. that are to be trapped and retained within the basin. or compacted earth placed on it to prevent flotation. iii. f. ii. and (2) the sediment itself which will have a high water content to the point of being “soupy.5 feet of stone. Relatively dry material can be handled with on-site equipment rather than the expensive draglines often needed to handle wet (underwatered) sediments. The plate shall have 2. iv.20 x upward forces). Usually. gravel. One very successful means of doing this is by use of a dewatering device. flyash. Collar spacing shall be between 5 and 14 times the vertical projection of each collar. Two approved bases for risers ten feet or less in height are: (1) a concrete base 18" thick with the riser embedded 9" in the base.” i. mechanical pumping. In either case. Dewatering shall be done in such a manner as to remove the relatively clean water without removing any of the sediment that has settled out and without removing any appreciable quantities of floating debris. If a dewatering device is needed it shall be included in the sediment basin plans submitted for approval and shall be installed during construction of the basin.4 .20 (Downward forces = 1. Anti-vortex device and trash rack .The riser shall have a base attached with a watertight connection and shall have sufficient weight to prevent flotation of the riser.1.2 of the Handbook. Collars shall be placed to increase the seepage length along the conduit by a minimum of 15 percent of the pipe length located within the saturation zone. Anti-Seep Collars . d. Base . Dewatering sediments trapped in a basin are often advantageous to the developer or contractor. and (2) a 1/4" minimum thickness steel plate attached to the riser by a continuous weld around the circumference of the riser to form a watertight connection. ii.4 .e. Dewatering the basin .anti-seep collars shall be installed around all conduits through earth fills of impoundment structures according to the following criteria: i. e. The assumed normal saturation zone (phreatic line) shall be determined by projecting a line at a slope of 4 horizontal to 1 vertical from the point where the normal water (riser crest) elevation touches the 6 6/05 3.There are two stages of dewatering the basin: (1) the detention pool which is below the crest of the riser and above the surface of the trapped sediment. the detention pool may be dewatered by a siphon installed on the riser.c. see Section 3.. For risers greater than ten feet high computations shall be made to design a base which will prevent flotatation. All collars shall be placed within the saturation zone. or other special materials. and surface or subsurface drains. less any reduction due to flow in the pipe spillway. 6 3. drainage easements will be obtained in accordance with local ordinances. the equation for revised seepage length becomes: 2(N)V = 1. including a means of conveying the discharge in an erosion-free manner to an existing stable channel. excavated plunge pools. The emergency spillway cross-section shall be trapezoidal with a minimum bottom width of eight feet. Erosion Protection . and a straight outlet section of at least 25 feet in length. a.Erosion protection shall be provided for by vegetation as prescribed in this publication or by other suitable means such as riprap. Emergency Spillways . c. Measures may include impact basin.5 6/05 . Freeboard . asphalt or concrete. This spillway channel shall have a straight control section of at least 20 feet in length. Velocities .The entire flow area of the emergency spillway shall be constructed in undisturbed ground (not fill). Protection against scour at the discharge end of the pipe spillway shall be provided.An outlet shall be provided.Freeboard is the difference between the design high water elevation in the emergency spillway and the top of the settled embankment. g.575(Ls) V Where: Ls = saturated length is length.4 . If there is no emergency spillway it is the difference between the water surface elevation required to pass the design flow through the pipe and the top of the settled embankment.15(Ls) or N = . When anti-seep collars are used. For channels with erosion protection other than vegetation. Where discharge occurs at the property line.The velocity of flow in the exit channel shall not exceed 5 feet per second for vegetated channels during a 10 year runoff event. 2. v. d.The minimum capacity of the emergency spillway shall be that required to pass the peak rate of runoff from the 10-year 24-hour frequency storm. Adequate notes and references will be shown on the erosion and sediment control plan. N= number of anti-seep collars. riprap. All fill located within this line may be assumed as saturated. of pipe between riser and intersection of phreatic line and pipe invert.1. revetment. The freeboard shall be at least one foot. Outlet . in feet. velocities shall be within the non-erosive range for the type of protection used. See the Standard and Specifications for Riprap Outlet Protection or Riprap Stilling Basin. or other approved methods. b.upstream slope of the fill to a point where this line intersects the invert of the pipe conduit. V= vertical projection of collar from pipe. All anti-seep collars and their connections shall be watertight. in feet. Capacity . 6 6/05 3. The point of inflow is the point that the stream enters the normal pool (pool level at the riser crest elevation). when L1 = L2. the length-width ratio computations are the same as shown above. In many cases the difference in elevation of the inflow and the bottom of the basin is considerable. any inflow point which conveys more than 30 percent of the total peak inflow rate shall meet the length-width ratio criteria. The required basin shape may be obtained by proper site selection. Then: We = A/Le and L:W ratio = Le/We Three examples are shown on Sheet 9 of the Standard Detail and Specification for Temproary Sediment Basin. The baffle length shall be as required to provide the minimum 2:1 length-width ratio.4 . The pool area (A) is the area of the normal pool. the water is allowed to go around both ends of the baffle and the effective length. Diversions. the pool area at the elevation of the crest of the principal spillway shall have a length to width ratio of at least 2. Points of entry should be located so as to insure maximum travel distance of the incoming runoff to point of exit (the riser) from the basin. Considerable care should be given to the major points of inflow into basins. A baffle detail is also shown. The purpose of this procedure is to prescribe the parameters. The effective length (Le) shall be the shortest distance the water must flow from the inflow point around the end of the baffle to the outflow point..e.6 . The purpose of the baffle is to increase the effective flow length from the inflow point to the riser.0 to 1. by excavation or by constructing a baffle in the basin. This special case procedure for computing Le is allowable only when the two flow paths are equal. i.1. procedures and methods of determining and modifying the shape of the basin. Baffles shall be placed mid-way between the inflow point and the riser. The inside slopes shall be 2:1 or flatter. Note that for the special case in Example C. The length of the flow path (L) is the distance from the point of inflow to the riser (outflow point). Otherwise. grade stabilization structures or other water control devices shall be installed as necessary to insure direction of runoff and protect points of entry into the basin. The purpose of this requirement is to minimize the "shortcircuiting" effect of the sediment laden inflow to the riser and thereby increase the effectiveness of the sediment basin. Entrance of Runoff Into Basin Points of entrance of surface runoff into excavated basins shall be protected to prevent erosion. Procedure for Determining or Altering Sediment Basin Shape As specified in the Standard and Specification. outside slopes shall be 3:1 or flatter. Often a riprap chute at major points of inflow would eliminate gullying and sediment generation. Le = L1 + L2.Embankment Cross-Section The minimum top width shall be ten feet. The effective width (We) is found by the equation: We = A/Le and L:W ratio = L/We In the event there is more than one inflow point. thus creating potential for severe gullying and sediment generation. 4c) and the data required on the Standard Detail and Specification. The developer or owner shall check with local building officials on applicable safety requirements. The sediment shall be placed in such a manner that it will not erode from the site.7 6/05 . When the basin area is to remain open space the pond may be pumped dry.) 6 3. If temporary fencing of sediment basins is required. The basin shall be dewatered in accordance with the approved plan prior to removing or breaching the embankment.1.4 . or adjacent to a stream. Safety Sediment basins are attractive to children and can be very dangerous. Final Disposal When temporary structures have served their intended purpose and the contributing drainage area has been properly stabilized. Local ordinances and regulations must be adhered to regarding health and safety. the location of and type of fence shall be shown on the plan. (NOTE: Standard designs discussed previously do not require hydrologic computations. and shall include the stabilization of the sediment basin site. the embankment and resulting sediment deposits are to be leveled or otherwise disposed of in accordance with the approved sediment control plan. or floodplain. graded and back filled. and backfilled with a structural fill. Sediment shall not be allowed to flush into a stream or drainageway.Disposal The sediment basin plans shall indicate the method(s) of disposing of the sediment removed from the basin. then the basin material and trapped sediments must be removed.1. If the site is scheduled for future construction. The proposed use of a sediment basin site will often dictate final disposition of the basin and any sediment contained therein. The sediment shall not be deposited downstream from the basin. Disposal sites will be stabilized as required by an approved erosion and sediment control plan. safely disposed of. The sediment basin plans shall also show the method of removing the sediment basin after the drainage area is stabilized. INFORMATION TO BE SUBMITTED Temporary sediment basin designs and construction plans submitted for review to the regulatory authority shall include the completed hydrologic design computation worksheet (Figure 3. 2. Volume of storage computed as 3.4 .1.QPIPE = 52 . 6 6/05 3./acre of drainage area. Drainage area to the basin is less than 10 acres.11 = 41 cfs 3.Conditions Where Practice Applies: 1. 4.) TRASHRACK EMERGENCY SPILLWAY CREST 36" 20' 3' 1' 2 10' (MAX) 24" DIA.8 .4a Standard sediment basin design for drainage areas less than 10 acres NOTE: This graphic is for informational purposes only. An emergency spillway is required: QES = QPEAK .1. Data must be transfered to Standard Detail and Specifications for construction purposes.01 10' (MIN.F. A/Q10 > .600 C. RISER RISER CREST 1 3 1 25' 15" DIA. BARREL R-4 Riprap 14" THICK 5' X 5' SQUARE ANTI-SEEP COLLAR 4' X 4' CONC BASE 18" THICK 10' (MIN.) Figure 3. Conditions Where Practice Applies: 1.1.) TRASHRACK EMERGENCY SPILLWAY CREST 54" 20' 3. A/Q10 > .5' 1' 2 10' (MAX) 36" DIA./acre of drainage area.4 . 4.35 = 53 cfs 3.) Figure 3. 2. 6 3. Data must be transfered to Standard Detail and Specifications for construction purposes. BARREL R-4 Riprap 14" THICK 5' X 5' SQUARE ANTI-SEEP COLLAR 5' X 5' CONC BASE 18" THICK 10' (MIN. NOTE: This graphic is for informational purposes only.600 C. Volume of storage computed as 3. RISER RISER CREST 1 3 1 25' 24" DIA. An emergency spillway is required: QES = QPEAK . Drainage area to the basin is 10 to 20 acres.F.9 6/05 .QPIPE = 88 .01 10' (MIN.4b Standard sediment basin design for drainage areas from 10 to 20 acres.1. Min.. Barrel: Diam. 7. then req’d. Qps = (Q) ___________ x (cor. H = ______________inches. required volume = 134 cu. Min. ________’-_________” square.2 x _____________ ac. 6.fac.Computed by __________________Date________ Checked by ____________________ Date________ Project ______________________________________________________________________________________ Basin ID__________________________________Location________________________________________ Total area draining to basin. Qes = Qp10 . Excavate ______________ cu. yds. yds. DESIGN ELEVATIONS 13. z = ______:1. yds. y = __________ft. Min. drainage = _______________ cu. x ________ ac. Emergency Spillway Flow. H = ___________ft. Volume of basin* = ________________________________ = ___________________ cu. yds. 3. 2.) __________ = _____________cfs. attach runoff computation sheet). Width____________ft.__________inches. Qps = 0.4c Temporary sediment basin design worksheet 6 6/05 3.4 . yds. Use _______ collars. Note: If there is no emergency spillway.1. Entrance channel slope ________________% Exit channel slope ____________________% ANTI-SEEP COLLAR DESIGN 12. before cleanout = 67 cu._____________ = _______________cfs. pipe spillway capacity.___________________Acres. h = ____________ft.10 . 8. drainage = _____________ cfs. x _______ac. Riser: Diam. Elevation corresponding to scheduled time to clean out: _____________ Distance below top of riser (ft): ________________________ DESIGN OF SPILLWAYS Runoff 4.__________inches.. Qp10= ____________________ cfs (TR-55 or other appropriate method. Pipe Spillway (Qps) 5. Emergency Spillway Design 10. vol. yds.__________inches. Trash Rack: Diam. 11. Riser Crest = ___________________________ Emergency Spillway Crest = ___________________ Design High Water = ______________________ Top of Dam = ____________________________ *Surface area criteria: Pond Surface Area (A)/10 Year Peak Discharge (Q10) > . 9. Length ____________ft. Hp ______________ft.1. pipe slope = _________%. drainage = ___________________cu. Ls = ___________ft.Qps = ____________ . projection = ________ft.01 Figure 3. BASIN VOLUME DESIGN 1. Barrel length = ______________ft. Qps= Qp10 = _____________cfs. to obtain required capacity. even if only part may be disturbed.4j). 8.11 6/05 . 6. If volume of basin is not adequate for required storage. if there is no emergency spillway.4g). See Pipe Spillway Design Charts (Figure 3.1. 9. Minimum required detention volume is 134 cubic yards per acres from each acre of drainage area. 13. or one foot. See Riser Inflow curves (Figure 3. Surface area criteria is established such that the pond surface area (ac) during a 10-year frequency storm divided by the peak discharge (cfs) of the 10-year frequency storm shall have a ratio of at least 0. 6 3.1. The pipe shall be designed to carry Qp10 if site conditions preclude installation of an emergency spillway to protect the structure. and design Qes. Therefore. or if there is no emergency spillway.TEMPORARY SEDIMENT BASIN DESIGN DATA SHEET INSTRUCTIONS FOR USE OF FORM 1.4 . Determine value of “H” from field conditions. Minimum top of dam elevation requires 1. 4.1.0 ft. Use Figure 3. Values larger than 134 cubic yards per acre may be used for greater protection. If no emergency spillway is to be used.) 7. See Trash Rack and Anti-Vortex Device Design Table (Figure 3. giving reason(s).4f). 11.4h to obtain values of design depth of flow (Hp). Fill in design elevations. Compute volume using entire contributing drainage area. to the design high water.1. it is the elevation of the riser crest plus "h" required to handle the 10-year storm. The emergency spillway crest must be set no closer to riser crest than value of "h" which causes pipe spillway to carry the minimum required Q.4e). 3.1. 2. Design high water is the elevation of the emergency spillway crest plus the value of Hp. Peak rates of runoff values shall be based on USDA-NRCS methodology as outlined in TR 55 Urban Hydrology and/or TR 20 Project Formulation .4d or Figure 3. the elevation difference between spillways shall be equal to the value of "h". whichever is greater. NOTE: A method for dewatering shall be incorporated into the design.Hydrology. Qp. 12. (“H” is the interval between the centerline of the barrel pipe at the outlet and the emergency spillway crest or. 10.1.2 cfs per acre of drainage area. See Anti-Seep Collar Design Graph (Figure 3. excavate to obtain the required volume.01. so state. bottom width. 5. The principal spillway shall be designed to carry 0. Compute Qes by subtracting actual flow carried by the pipe spillway from the total inflow.1. of freeboard above design high water. 1.12 .1.4d Pipe flow chart for corrugated pipe drop inlet spillway (Source: NRCS Engineering Field Manual. Chapter 6) 3.4 .6 6/05 Figure 3. Chapter 6) 3.1.4e Pipe flow chart for smooth pipe drop inlet spillway (Source: NRCS.1.Figure 3.4 .13 6 6/05 . Engineering Field Manual. 1.14 .6 6/05 Figure 3.1.4f Riser inflow curves (Source: USDA-NRCS-MD) 3.4 . 15 6 6/05 .Figure 3.1.4g Trash rack and anti-vortex design table (Source: USDA-NRCS-MD) 3.4 .1. 6 6/05 Figure 3.4h Emergency spillway design table (Source: NRCS.4 .0 and 1.5 feet must fall within the following ranges for this table to be used. Engineering Field Manual.1.16 .1. Chapter 11) 3.The exit slopes for emergency spillways with flow depths of 1. Anti-Seep Collar Design This procedure provides the anti-seep collar dimensions for only temporary sediment basins to increase the seepage length by 15% for various pipe slopes.25-Sp Where: Ls = length of pipe in the saturated zone (ft. vertical.) Ls = Y (z + 4) 1 + Sp 0. The first step in designing anti-seep collars is to determine the length of pipe within the saturated zone of the embankment. embankment slopes and riser heights.1.4. (See Figure 3. assuming that the upstream slope of the embankment intersects the invert of the pipe at its upstream end.1i below for embankment-invert intersection. Sp = slope of pipe in feet per foot.1.1.) Y = distance in feet from upstream invert of pipe to highest normal water level expected to occur during the life of the structure.4 . This procedure is based on the approximation of the phreatic line as shown in Figure 3. This can be done graphically or by the following equation.4i below: RISER CREST EMBANKMENT Y EMBANKMENTINVERT INTERSECTION φ Z:1 COLLAR PROJECTION V ASSUMED PHREATIC LINE Ls 4:1 PIPE DIAMETER Figure 3.4i Terminilogy for anti-seep collar design 3.17 6 6/05 . usually the top of the riser. Z = slope of upstream embankment as a ratio of z ft. horizontal to one ft. 1.6 6/05 Figure 3.18 .4 .4j Anti-seep collar design graph (Source: USDA-NRCS-MD) 3.1. (Dr) Pipe material Length of pipe (L) Pipe dia.) Crest of riser (El) Riser dia. width (b) Anti-seep collars (No. (L X W) Collar spacing (Ft) See Sheet 3 of 11 for req'd trash rack/anti-vortex device data Source: DE ESC Handbook Symbol: Detail No.S.S. 1:1 Dp Cut-off trench Attachm't for dewatering device or skimmer Riser base (see Sheet 8 of 11) 4' Min. depth (d) E. Riser crest Water-tight coupling (typ. (Dp) Pipe inverts (El) Crest of e.) (see Sheets 4-6 of 11 ) Crest E. (El) Embankment top width (TW) Top of embankment (El) Angle of pipe at riser (Deg. Min.Standard Detail & Specifications Temporary Sediment Basin TW. 10' Trash rack/antivortex device (see Sheet 3 of 11) Anti-seep collar (typ.) (see Sheet 7 of 11) 1 2 Dr Temp. 1' min.1.A. Outlet protection (see separate detail) Section thru P rincipal Spillway Principal DATA Drainage area (D. TSB DE-ESC-3.S.) Required storage (VS) Design dimensions (L x W x D) Clean-out elev.) Collar dim.s. (El) E.4 Sheet 1 of 11 12/03 Date: _________________ . storage 1 3 1:1 Wet storage 2' Min. TSB DE-ESC-3.4 Sheet 2 of 11 12/03 Date: _________________ .Standard Detail & Specifications Temporary Sediment Basin Emer gency Spillway D etails Emergency Details Plan Profile Cross-section Source: Symbol: Adapted from USDA-NRCS Detail No.1. Source: Adapted from MD Stds. Support bars are welded to the top of the riser or attached by straps bolted to top of riser. Pressure relief holes may be omitted.4 Sheet 3 of 11 12/03 Date: _________________ Date: _________________ . The cylinder must be firmly fastened to the top of the riser. = __________ H = __________ Notes: 1. 2. for ESC Symbol: Detail No.TTrrash Rack and Anti-V or tex D evice Anti-Vor ortex Device Data Top stiffener (if required) is ____x____x____ angle welded to top and oriented perpendicular to corrugations. if ends of corrugations are left fully open when corrugated top is welded to cylinder. Top is _____ gage corrugated metal or 1/8" steel plate. & Specs. TSB DE-ESC-3. Cylinder is ____ gage corrugated metal pipe or fabricated from 1/8" steel plate.Standard Detail & Specifications Temporary Sediment Basin Detail .1. Dia. Standard Detail & Specifications Temporary Sediment Basin Detail .1. for ESC Symbol: Detail No. DE-ESC-3. & Specs.4 TSB Sheet 4 of 11 12/03 Date: _________________ .One-Piece Metal Anti-Seep Collar Source: Adapted from MD Stds. TSB E-ESC-3.1.TTwo-Piece wo-Piece Corrugated Metal Anti-Seep Collar Detail .TTwo-Piece wo-Piece Helical Pipe Anti-Seep Collar Source: Adapted from VA ESC Handbook Symbol: Detail No.4 Sheet 5 of 11 12/03 Date: _________________ .Standard Detail & Specifications Temporary Sediment Basin Detail . 5. butyl rubber or neoprene. 2. 7. 3. away from the pipe. 4.1. The center membrane section may be 1/16 inch gum rubber.Standard Detail & Specifications Temporary Sediment Basin Detail . Cut a hole. The antiseep material shall be fastened to the pipe using a stainless steel clamp. Source: Adapted from IL Urban Manual Symbol: Detail No. Butyl Rubber A W= Or Neoprene Membrane ELEVATION SECTION A-A NOTES: 1. Helical pipe shall have a mastic sealer applied at the collar location.Flexible Anti-Seep Collar 1" X 4" Lumber Stainless Steel Plastic Sheet Clamp W/2 A Frame Dia Pipe W/2 W= Flow Gum Rubber. 6. Completed installation must be watertight. Butyl Rubber Or Neoprene Sheet Of Non-Reinforced Gum Rubber. DE-ESC-3.4 TSB Sheet 6 of 11 12/03 Date: _________________ . 3 inches smaller than the diameter of the pipe. The outer portion of the antiseep collar. may be made of a minimum 20 mil plastic sheet. The entire antiseep may be made of these materials. The sealer will not be required for PVC or annular pipe. centered on the material used at the pipe and force it over the end of the pipe. Care must be taken to back fill equally on both sides of the antiseep collar. 1. for ESC Symbol: Detail No.Standard Detail & Specifications Temporary Sediment Basin Detail .4 Sheet 7 of 11 12/03 Date: _________________ . & Specs.W ater-Tight Connectors Water-Tight Source: Adapted from MD Stds. TSB DE-ESC-3. for ESC Symbol: Detail No.Standard Detail & Specifications Temporary Sediment Basin RISER B ASE DET AIL BASE DETAIL Notes: 1. The concrete base shall be poured in such a manner to insure that the concrete fills the bottom of riser to the invert of the outlet pipe to prevent the riser from breaking away from the base. Source: Adapted from MD Stds. 3.1. the embedded section must be painted with zinc chromate or equivalent.2. With aluminum or aluminized pipe. Riser base may be sized as computed using floatation with a factor of safety of 1. & Specs. 2.4 Sheet 8of 11 12/03 Date: _________________ . TSB DE-ESC-3. 4 Sheet 9 of 11 12/03 Date: _________________ .Standard Detail & Specifications Temporary Sediment Basin Example B affle Configur ations Baffle Configurations Source: Adapted from MD Stds.1. & Specs. TSB DE-ESC-3. for ESC Symbol: Detail No. or other objectionable material. GP. 2. TSB DE-ESC-3. placed over it to prevent flotation. The barrel and riser shall be placed on a firm. It shall be clean mineral soil free of roots. trees. The minimum bottom width shall be four feet.Standard Detail & Specifications Temporary Sediment Basin Construction Notes: 1. 3. rocks. Pervious materials such as sand. The minimum depth shall be two feet. All connections between barrel sections must be achieved by approved watertight band assemblies. gravel. the pool area (measured at the top of the pipe spillway) will be cleared of all brush. Steel base plates on risers shall have at least 2-1/2 feet of compacted earth. Source: DE ESC Handbook Symbol: Detail No. In order to facilitate clean-out and restoration. but wide enough to permit operation of excavation and compaction equipment. Embankment The fill material shall be taken from approved areas shown on the plans. it is too wet for proper compaction. If water can be squeezed out of the ball.1. A minimum depth of two feet of hand compacted backfill shall be placed over the pipe spillway before crossing it with construction equipment. The barrel stub must be attached to the riser at the same percent (angle) of grade as the outlet conduit. Cut-off-trench A cut-off trench shall be excavated along the centerline of earth fill embankments. The cut-off trench shall extend up both abutments to the riser crest elevation. The fill material around the pipe spillway shall be placed in four inch layers and compacted by means of a manually directed power tamper under and around the pipe to at least the same density as the adjacent embankment. Relatively pervious materials such as sand or gravel (Unified Soil Classes GW. The embankment shall be constructed to an elevation 10 percent higher than the design height to allow for settlement. or crushed stone shall not be used as backfill around the pipe or anti-seep collars.4 Sheet 10 of 11 12/03 Date: _________________ . smooth foundation of impervious soil. Pipe Spillways The riser shall be securely attached to the barrel or barrel stub by welding the full circumference making a watertight connection. 4. grubbed. The side slopes shall be no steeper than 1:1. oversized stones. Compaction shall be obtained by routing and hauling the construction equipment over the fill so that the entire surface of each layer of the fill is traversed by at least one wheel or tread track of the equipment or by the use of a compactor. woody vegetation. Compaction requirements shall be the same as those for embankment. The trench shall be dewatered during the backfilling and compaction operations. and other objectionable materials. SW & SP) shall not be placed in the embankment. The connection between the riser and the riser base shall be water tight. Fill material shall be placed in six-inch to eight-inch thick continuous layers over the entire length of the fill. Areas on which fill is to be placed shall contain sufficient moisture so that it can be formed by hand into a ball without crumbling. and stripped of topsoil. Site Preparation Areas under the embankment shall be cleared. The proposed use of a sediment basin site will often dictate final disposition of the basin and any sediment contained therein. Final Disposal When temporary structures have served their intended purpose and the contributing drainage area has been properly stabilized. 6. Maintenance a. Safety State and local requirements shall be met concerning fencing and signs.) 5.1. Dewatering operations shall be conducted in accordance with any and all regulatory requirements. This sediment shall be placed in such a manner that it will not erode from the site. or adjacent to a stream or floodplain. 8. warning the public of hazards of soft sediment and floodwater. Vegetative Treatment Stabilize the embankment and emergency spillway in accordance with the appropriate Vegetative Standard and Specifications immediately following construction. When the basin area is to remain open space the pond may be pumped dry. then the basin material and trapped sediments must be removed. The achievement of planned elevations. Emergency Spillway The emergency spillway shall be installed in undisturbed ground. 7. 9. If the site is scheduled for future construction.Standard Detail & Specifications Temporary Sediment Basin Construction Notes (cont. Sediment shall be removed from the basin when it reaches the specified distance below the top of the riser. entrance and exit channel slopes are critical to the successful operation of the emergency spillway and must be constructed within a tolerance of + 0. Repair all damages caused by soil erosion and construction equipment at or before the end of each working day.4 Sheet 11 of 11 12/03 Date: _________________ . b.2 feet. The sediment shall not be deposited downstream from the embankment. safely disposed of. the embankment and resulting sediment deposits are to be leveled or otherwise disposed of in accordance with the approved sediment control plan. In no case shall the embankment remain unstabilized for more than seven (7) days. grades. c. design width. Source: DE ESC Handbook Symbol: Detail No. TSB DE-ESC-3. and backfilled with a structural fill. graded and backfilled. An approved dewatering device shall be considered an integral part of the basin. Source: Symbol: Detail No. 12/03 Date: _________________ .Standard Detail & Specifications Temporary Sediment Basin This page left intentionally blank. this type of inlet protection is inherently less effective than the Type 1 inlet protection.This type of inlet protection is typically used in open space areas and is the preferred type when site conditions allow. etc. Conditions Where Practice Applies This practice shall be used where the drainage area to an inlet is disturbed. it is not possible to temporarily divert the storm drain outfall into a sediment trapping device and watertight blocking of inlets is not advisable.This type of inlet protection shall only be used in situations in which the Type 1 inlet protection can not be installed. Type 2 . There are two (2) general types of inlet protection: 1. such as impervious surfaces. 6 3.1.STANDARD AND SPECIFICATIONS FOR STORM DRAIN INLET PROTECTION Definition: A barrier installed around inlets or across an opening to temporarily pond sediment-laden water. The designer should be aware of this and allow the necessary flexibility in the sequence of construction. Type 1 . It may be necessary to change from one type of inlet protection to the other during the normal course of construction. Purpose: To prevent sediment-laden water from entering a storm drain system through inlets.5 .1 12/03 . partially completed roads. It is not to be used in place of sediment trapping devices. Since there is no temporary ponding of sediment-laden runoff. thereby reducing the sediment content. 2. Optimal performance requires some temporary ponding of water to allow sedimentation to occur. This page left intentionally blank.5 .2 .1. 6 12/03 3. Standard Detail & Specifications Inlet Protection . 36" Max. all 4 sides 18" Max. Inlet NOTE: Pre-manufactured inlet protection devices such as Silt-Savertm.5. McCullah & Assoc. provide overlap at last section Ponding height 2"x4" wood frame w/wire mesh backing. 12" Min. Symbol: Detail No.1 Sheet 1 of 2 12/03 Date: _________________ . IP-1 DE-ESC-3.1.Type 1 A Grate 5% slope or flatter A Plan Top frame required Attach GD-II geotextile fabric securely to 2"x4" wood frame. Section A-A Source: Adapted from Erosion Draw Manual J. are an acceptable subsitute under this standard. or equivalent. Excavate completely around inlet to a depth of 18" below grate elevation. the cloth must extend from top of frame to 18" below inlet grate elevation. 4. Drive 2" x 4" post 1' into ground at four corners of inlet. 5. Fasten securely to frame.Standard Detail & Specifications Inlet Protection .1. Materials: 1. The top of this dike is to be at least 6" higher than the top of frame (weir). McCullah & Assoc. Ends must meet at post. from Erosion Draw Manual J. Backfill around inlet in compacted 6" layers until at least 12" of geotextile fabric is buried. 2. Ends must meet at post. Wire mesh must be of sufficient strength to support filter fabric with water fully impounded against it. then fastened down. construct a compacted earth dike in the ditchline below it. 2. 7. 6. 3.5. Place nail strips between posts on ends of inlet.Type 1 Construction Notes: 1. This structure must be inspected frequently and the filter fabric replaced when clogged. Geotextile fabric: Type GD-II Source: Adapted. Assemble top portion of 2" x 4" frame using overlap joint shown. If the inlet is not in a low point. Wooden frame is to be constructed of 2" x 4" construction grade lumber.1 Sheet 2 of 2 12/03 Date: _________________ . Top of frame (weir) must be 6" below edge of roadway adjacent to inlet. Symbol: Detail No. be overlapped and folded. IP-1 DE-ESC-3. 3. Stretch wire mesh tightly around frame and fasten securely. Stretch geotextile fabric tightly over wire mesh. ) Perspectiv erspectivee Source: Adapted from ACF Products.1.2 Sheet 1 of 2 12/03 Date: _________________ .Standard Detail & Specifications Inlet Protection . Expansion restraint (1/4" nylon rope w/2" flat sashers) Bag D etail Detail Dump strap 1" rebar for bag removal from inlet Dump strap GD-III geotextile inlet insert (ACF Hi-Flow Siltsack or approved equiv. 2 ea.5. Symbol: Detail No.Type 2 Dump straps. Inc. IP-2 DE-ESC-3. Source: Adapted from ACF Products. IP-2 DE-ESC-3. streets.5.Type 2 Notes: 1. Inc.2 Sheet 2 of 2 12/03 Date: _________________ . It may be necessary to transition from Type 1 to Type 2 Inlet Protection as construction proceeds.Type 1 cannot be used due to site constraints. roads. For areas where there is a concern for oil run-off or spills. 2.1. Symbol: Detail No. These include. Materials: The geotextile inlet insert shall meet or exceed the specifications of Type GD-III geotextile in accordance with Appendix A-3 of the Delaware Erosion & Sediment Control Handbook. etc. 3.Standard Detail & Specifications Inlet Protection . but are not limited to partially completed parking areas. This practice shall only be used in situations in which Inlet Protection . insert shall meet one of the above specifications with an oil-absorbant pillow or shall be made completely from an oilabsorbant material with a woven pillow. Purpose: To prevent sediment-laden water from entering a culvert and being conveyed downstream. 6 3. Conditions Where Practice Applies This practice shall be used where the drainage area to a culvert is disturbed.6 .STANDARD AND SPECIFICATIONS FOR CULVERT INLET PROTECTION Definition: A barrier installed across a culvert entrance to temporarily pond sediment-laden water. It is not to be used in place of sediment trapping devices.1. thereby reducing the sediment content. it is not possible to temporarily divert the runoff into a sediment trapping device and watertight blocking of the culvert is not advisable.1 12/03 . This page left intentionally blank.2 . 6 12/03 3.6 .1. 1.0' DE No.5' 1.5' 2.6 Sheet 1 of 2 12/03 Date: _________________ .5: Flow 1M ax. CIP DE-ESC-3.Standard Detail & Specifications Culvert Inlet Protection Culvert Toe of slope Toe of slope Silt fence (Use stone option for concentrated flows) * *Provide min. 57 stone (Type GD-II geotextile optional) R-6 Riprap Section .Silt F ence Option Fence 1.1.Stone Option Source: Adapted from VA ESC Handbook Symbol: Detail No. 6' clearance Silt fence must be tied into toe of slope so as to prevent by-pass flow Flow Plan . Envirofence. Reinforcing strip: Wooden lath. Stakes: Steel either T or U or 2" hardwood.1. 3. or approved equivalent. plastic strip or other approved equivalent. Riprap: R-6 Source: Adapted from VA ESC Handbook Symbol: Detail No. Stone: DE No. Geotextile: Type GD-1 for silt fence option Type GD-II for stone/riprap option 3.1. Placement of the silt fence or stone barrier should be in a "horseshoe" shape and provide a minimum of 6 feet of clearance from the culvert inlet.6 Sheet 2 of 2 12/03 Date: _________________ . the stone option shall be employed. 4.Standard Detail & Specifications Culvert Inlet Protection Construction Notes 1. 57 6. Additional filtration may be provided by using a Type GD-II geotextile incorporated into the design as an option. Materials 1. 2. CIP DE-ESC-3. If silt fence can not be installed properly or flow conditions exceed the design capabilities of silt fence. 5. Silt fence shall be designed and installed in accordance with the Standard Detail and Specifications for Silt Fences (DE-ES-3.2). Prefabricated Unit: Geofab. 2. ) x 32 = Cubic Foot Storage.STANDARD AND SPECIFICATIONS FOR PORTABLE DEWATERING PRACTICES Definition: A portable device through which sediment-laden water is pumped to trap and retain the sediment. and rights-of-way below a project site. Conditions Where Practice Applies A portable dewatering practice may be used on sites where space is limited. Size In the absence of other sizing criteria.2. where direct discharge of sediment-laden water to stream and storm drainage systems is to be avoided and where larger dewatering practices are impractical. Other container designs may be used if the storage volume is adequate and approval is obtained from the local approving agency. adjoining properties. Details for a portable sediment tank and a geotextile dewatering bag are included in the Handbook. 6 3. Design Criteria Location The portable dewatering practice shall be located for ease of clean-out and disposal of the trapped sediment. and to minimize the interference with construction activities and pedestrian traffic.M.1 12/03 .1 .P. the following formula should be used in determining the storage volume of the portable dewatering practice: Pump Discharge (G. such as urban construction. Purpose: To trap and retain sediment prior to pumping the water to drainageways. 1 .2 .2. 6 12/03 3.This page left intentionally blank. 2.f. 1/4" wire mesh Geosynthetic fabric 2' cleanout depth 1/2" steel plate (water-tight weld) Section Eye bolt Inflow Plan Construction Notes: 1. 2.1.C.Standard Detail & Specifications Portable Sediment Tank Eye bolt Inflow Outflow 72" CMP 5' CMP section 60" CMP with 1" dia. perforations at 6" O. & Specs. storage/1 gpm pump discharge. for ESC Symbol: Detail No. Source: Adapted from MD Stds. ST DE-ESC-3.1 Sheet 1 of 1 12/03 Date: _________________ . Required storage volume = 1 c. Tanks may be connected in series to provide required storage. Standard Detail & Specifications Portable Sediment Tank This page left intentionally blank. 12/03 Date: _________________ . Source: Symbol: Detail No. 1. Inc.) Flow Pump discharge hose Length Plan Aggregate underlayment Profile Source: Adapted from ACF Products.2. Symbol: Detail No.Standard Detail & Specifications Width Geotextile Dewatering Bag High strength strapping Geotextile dewatering bag (ACF Dirtbag or approved equiv. GB DE-ESC-3.2 Sheet 1 of 2 12/03 Date: _________________ . Seam strength test will have the following minimum average roll values: Type Heavy duty TEST METHOD ASTM D-4884 TEST RESULT 100 lb / in 3. visible fabric removed and seeded or removed from site to a proper disposal area. Disposal may be accomplished as directed by the construction reviewer. it should be replaced with a new bag.1. The geotextile fabric shall be a Type GD-IV. the bag may be buried on site and seeded. The dewatering bag is considered full and should be disposed when it is impractical for the bag to filter the sediment out at a reasonable flow rate. Source: Adapted from ACF Products. 2. The dewatering bag should be placed on a gravel bed to allow water to flow in all directions. At this point. The dewatering bag should be placed so the incoming water flows into and through the bag. Materials: 1. All structural seams will be sewn with high strength.Standard Detail & Specifications Geotextile Dewatering Bag Construction Notes: 1. 3.2. double stitched “J” type. and then flow off the site without creating more erosion. Inc. Symbol: Detail No. The dewatering bag shall have an opening large enough to accommodate a four (4) inch discharge hose with attached strap to tie off the hose to prevent the pumped water from escaping from the bag without being filtered. 2. If the site allows. GB DE-ESC-3.2 Sheet 2 of 2 12/03 Date: _________________ . The dewatering bag shall be sewn with a double needle machine using high strength thread. The neck should be tied off tightly to stop the water from flowing out of the bag without going through the walls. 6 3. They may also be used to collect and filter water during the excavation phase of construction. Discharge of water pumped from the standpipe should be to a stabilized area. Purpose: To remove excess water from excavations and/or traps.2 .2.STANDARD AND SPECIFICATIONS FOR PUMPING PIT Definition: A temporary pit which is constructed to trap and filter water for pumping to a suitable discharge area. Conditions Where Practice Applies Pumping pits are primarily used to de-water other erosion and sediment control practices such as sediment traps and basins. If water from the pit will be pumped directly to a storm drainage system or free flowing stream. Design Criteria The type of pumping pits and their locations should be shown on the plan. Water is then pumped from the center of the pipe to a suitable discharge area. This will increase the rate of water seepage into the standpipe. It is recommended that 1/4-1/2 inch hardware cloth wire be wrapped around and secured to the standpipe prior to attaching the filter cloth. a Type GD-II (see Appendix A-3) geotextile should be wrapped around the standpipe to ensure clean water discharge. A design is not required but construction should conform to the general criteria outlined on Standard Drawing. such as during excavation for structural foundations.1 12/03 . A perforated vertical standpipe is placed in the center of the pit to collect filtered water. 2 .2. 6 12/03 3.This page left intentionally blank.2 . prior to attaching the geotextile fabric. 4. PP-1 DE-ESC-3. for ESC Symbol: Detail No. 2.C. This will increase the rate of water seepage into the pipe. Pit dimensions are variable. A base of DE #57 aggregate should be placed in the pit to a depth of 12". perforations at 6" O.1 Sheet 1 of 1 12/03 Date: _________________ . If desired.Standard Detail & Specifications Pumping Pit . NOTE: If discharge will be pumped directly to a storm drainage system. Place 12" of DE #57 stone before installing stand pipe Water-tight cap or plate Section Construction Notes: 1. Top of standpipe to extend min. 12"-18" above water level Standpipe wrapped with Type GD-II geotextile fabric DE #57 Stone Side slope (varies) 12"-24" corrugated metal or plastic pipe with 1" dia. the standpipe must be wrapped with Type GD-II geotextile fabric before installation. After installing the standpipe. Source: Adapted from MD Stds. The perforations shall be 1/2" X 6" slits or 1" diameter holes 6" on center.2. 1/2" hardware cloth may be placed around the standpipe.2. The standpipe should be constructed by perforating a 12" to 24" diameter corrugated or PVC pipe. 3. The standpipe should extend 12" to 18" above the lip of the pit or riser crest elevation (basin dewatering). the pit surrounding the standpipe should then be backfilled with DE #57 aggregate.Type 1 Suction line to pump Clean water discharge 3" min. & Specs. Source: Symbol: Detail No. 12/03 Date: _________________ .Standard Detail & Specifications Pumping Pit .Type 1 This page left intentionally blank. C. perforations at 6" O. & Specs.2 Sheet 1 of 2 12/03 Date: _________________ . Weight as necessary to prevent flotation of inner pipe 8' min.2. for ESC Symbol: Detail No.Standard Detail & Specifications Pumping Pit . perf. at 6" O. Section Source: Adapted from MD Stds.Type 2 Hook and chain for removal 24"-36" corrugated metal or plastic pipe with 1" dia. DE #57 stone 36"-48" corrugated metal or plastic pipe with 1" dia. PP-2 DE-ESC-3.C. Water level 3" min.2. PP-2 DE-ESC-3.2. the standpipe must be wrapped with Type GD-II geotextile fabric before installation.2. Source: Adapted from MD Stds. The inside standpipe should be constructed by perforating a 24" to 36" diameter corrugated or PVC pipe. 2. 4. Pit shall have a minimum bottom width of 8'.2 Sheet 2 of 2 12/03 Date: _________________ . After installing the standpipes. This will increase the rate of water seepage into the pipe. prior to attaching the geotextile fabric. 3" above the design high water elevation in the trap or basin. The height of the stone shall be a min. the pit surrounding the standpipes should then be backfilled with DE #57 aggregate. 5. The perforations shall be 1/2" X 6" slits or 1" diameter holes 6" on center. for ESC Symbol: Detail No. NOTE: If discharge will be pumped directly to a storm drainage system. The standpipes should extend 12" to 18" above the design high water elevation in the trap or basin.Type 2 Construction Notes: 1. 3. & Specs. If desired.Standard Detail & Specifications Pumping Pit . 1/2" hardware cloth may be placed around the standpipe. The outside pipe shall be at least 12" larger in diameter than the inside pipe. it may not function at all. Devices utilizing perforated pipe shall provide an adequated number of perforations to maintain its function should partial clogging occur. Purpose: To allow sediment-laden runoff to be filtered prior to being discharged to a suitable outlet.2 shall be used for gravity-type anti-flotation devices. The device shall have an anchor or other means provided to prevent flotation. Experience has also shown that if the connection pipe from the skimmer to the outlet structure is entirely constructed with flexible pipe. 2. Skimmer .) The filtering media shall consist of a Type GD-II (see Appendix A-3) geotextile fabric wrapped around the perforated section of pipe. bands. Filter media should be replaced as needed. (A factor of safety of 1.2. This section shall then be blinded with DE #57 stone. In general. the filtering media shall consist of a Type GD-II (see Appendix A-3) geotextile fabric wrapped around the perforated portion of the skimmer and attached with plastic snap ties. If the skimmer floats too high. Conditions Where Practice Applies: Dewatering devices are appropriate where the discharge from a sediment trapping structure can be accomplished via gravity flow. skimmer-type dewatering devices may also be used for pump-out type dewatering activities. the skimmer dewatering device shall be the preferred option. Pipe Dewatering Device .3 .1 12/03 . leaving the sediment trapping structure without adequate volume for subsequent runoff events. If additional filtration is necessary. it is prone to floatation and will inhibit proper functioning.STANDARD AND SPECIFICATIONS FOR DEWATERING DEVICE Definition: An appurtenace to a sediment trapping structure typically consisting of perforated pipe with a filtering media. Design Criteria: The dewatering device shall be designed in such a manner so as to remove the relatively clean water without removing any of the sediment that has settled out and without removing any appreciable quantities of floating debris.A fixed pipe-type dewatering device shall be configured as a vertical perforated riser connected to the principal outlet structure with an elbow.Skimmers must be designed so as to float just beneath the water surface in order to remove sediment-laden water most efficiently. Maintainance: Dewatering devices should be inspected after each runoff event to ensure they are functioning properly. etc. Under some circumstances. Some additional criteria for specific types of devices are as follows: 1. 6 3. 3 .2 .2.This page left intentionally blank. 6 12/03 3. S.90o Tee 4" solid PVC flotation section w/caps and elbows Overlapped connecting bands 4" perf.E.3. SDD DE-ESC-3. PVC skimming section w/caps Plan Flotation section mounted above skimming section #4 Rebar guide post (typ. Symbol: Detail No.Standard Detail & Specifications Skimmer Dewatering Device Wall of outlet structure 12" 4 LF of 4" flexible pipe 18" Wire stop 24" 4 LF of 4" solid PVC pipe 4".1 Sheet 1 of 2 12/03 Date: _________________ . Skimming section DE #57 stone pad Flexible pipe Profile thru CL of Pipe Source: Adapted from drawing by Vandemark & Lynch.2. w/wire stop set @ top of riser W.). Inc. Standard Detail & Specifications Skimmer Dewatering Device Construction Notes: 1. If additional filtration is necessary.) . Skimmer section shall have (12) rows of 1/2" dia. 6.4" Sched. 2. holes. 3. SDD DE-ESC-3.1 Sheet 2 of 2 12/03 Date: _________________ . 40 PVC Perforated pipe . 5. Solid pipe .4" Sched.) . 4. 4. more frequent inspection may be necessary. 6. 40 PVC 90o Tee (1 ea.) . 40 PVC 90o Elbow (2 ea. bands. solid Flexible pipe . 2.2.4" Sched. 40 PVC. 40 PVC Cap (4 ea. Construction operations shall be carried out in such a manner that erosion and water pollution are minimized. the structure shall be inspected after each rain and repairs made as needed. the filtering media shall consist of a Type GD-II geotextile fabric wrapped around the perforated portion of the skimmer and attached with plastic snap ties. 1-1/4" on center. etc.4" Sched. Flexible pipe shall be inserted into solid pipe and fastened with (2) #8 wood screws. At a minimum. Pipe flotation section shall be solvent welded to ensure an airtight assembly. Materials: 1. Contractor to conduct a test to check for leaks prior to installation.4" corrugated plastic tubing (non-perforated) Source: Delaware ESC Handbook Symbol: Detail No. If vandalism is a problem. 5. The structure shall only be removed when the contributing drainage area has been properly stabilized.4" Sched. 3.3. 2 Sheet 1 of 2 12/03 Date: _________________ . 6 ") C of Pipe Profile thru L DATA Standpipe diameter Connector pipe diameter Source: Adapted from IL Urban Manual Symbol: Detail No. 1" perf. PDD DE-ESC-3. Type GD-II geotextile fabric Temp. at 6" O.2.Standard Detail & Specifications Pipe Dewatering Device Min. 6" CMP or plastic standpipe with cap.C.3. Storeage Riser DE #57 stone Barrel Wet Pool 12" thick concrete or 1/4" steel plate Solid CMP or plastic connector pipe (Min. Steel plate bases will be 1/4 inch minimum thickness attached to the standpipe by a continuous weld around the bottom to form a watertight connection. 7.2 Sheet 2 of 2 12/03 Date: _________________ .2. The riser shall be wrapped with a Type GD-II geotextile fabric. Source: Adapted from IL Urban Manual Symbol: Detail No. Standpipe and connector pipe shalll be a minimum of 6" in diameter. 3. Straps or connecting bands shall be used to hold the fabric and wire mesh (as needed) in place. 4. gravel or tamped earth placed on it. Metal pipe may be galvanized steel or aluminum. The top 2/3 of the standpipe shall be perforated with one (1) inch diameter hole or slit spaced six (6) inches vertically and horizontally and placed in the concave portion of pipe. PDD DE-ESC-3. 40 PVC or HDPP. No holes will be allowed within six (6) inches of the horizontal connector pipe. 9. The standpipe shall be anchored with either a concrete base or steel plate base to prevent flotation. Where ends of fabric come together. 8. Construction operations shall be carried out in such a manner that erosion and water pollution are minimized. The structure shall only be removed when the contributing drainage area has been properly stabilized. Concrete bases shall be 12 inches thick with the standpipe embedded nine (9) inches. The plate shall have 2. The structure shall be inspected after each rain and repairs made as needed. They shall be placed at the top and bottom of the cloth.5 feet of stone.Standard Detail & Specifications Pipe Dewatering Device Construction Notes: 1. 5. 2. folded and stapled to prevent bypass. 10. they shall be overlapped. The fabric shall extend six (6) inches above the highest hole and six (6) inches below the lowest hole. 6.3. plastic pipe may be Sched. All pipe connections shall be watertight. Once the sediment build-up prevents the structure from functioning as designed. If sediment-laden water is to be filtered at the intake line. 3. refer to Section 3. the sediment shall be removed. The stockpile shall be protected with perimeter controls and stabilized in accordance with the Standard and Specifications for Vegetative Stabilization. Material which is excavated to construct the basin shall be stockpiled nearby so as to be readily available for restoration when the basin is no longer needed. 6 3. Conditions Where Practice Applies: Dewatering basins are appropriate whenever sediment-laden water can not be filtered by a gravity-type dewatering device.4 . spread on-site and stabilized or disposed of at an approved disposal site in accordance with the approved plan. 2.2. Furthermore.2.1 12/03 . ft. Design Criteria 1.) x 16 = required volume of storage (cu.p.) 2. Purpose: To filter sediment-laden pump discharge water prior to its release to a suitable outlet. they are intended to be used at the discharge line from a pump.STANDARD AND SPECIFICATIONS FOR DEWATERING BASIN Definition: A temporary settling and filtering structure used for dewatering activities.m. Standard and Specifications for Pumping Pit. The dewatering basin must be sized and operated to allow pumped water to flow through the filtering device without overtopping the structure. The dewatering basin shall be inspected regularly during each day of operation to ensure it is not being overloaded.2. The minimum volume provided in the basin shall be based on the following fomula: Pump discharge (g. Maintenance 1. The inside of the basin may be lined with geotextile fabric to help reduce scour within the basin itself. This page left intentionally blank.4 . 6 12/03 3.2.2 . ) Min.6" 2:1 DE #57 stone Excavated area Section B-B Source: Adapted from VA ESC Handbook Symbol: Detail No. 4" Excav.4. area Flat bottom Section A-A Flow 2:1 1' .1 Sheet 1 of 2 12/03 Date: _________________ .Standard Detail & Specifications Dewatering Basin . area NOTE: Geotextile fabric covers entire inside face of straw bales. 6' square Excav.Type 1 R-5 riprap splash block 1' depth Type GD-II geotextile Pump discharge 2 stakes per bale (Typ. DWB-1 DE-ESC-3.2. B 3' DE #3 stone A A B R-5 riprap Plan Existing ground 6" 3' min. Available volume shall be measured from the floor of the excavation to the crest of the stone weir. of 6 hours of sediment settling time. of 3' below the base of the straw bales. Capacity of the basin shall be based on the following formula: Pump discharge (gpm) x 16 = cubic feet of storage required 2. 3. 6. 5. The excavated area shall be a min. Once the wet storage area becomes filled to one-half of the excavated depth. The wet storage area may be dewatered only after a min. DWB-1 DE-ESC-3. 4. accumulated sediment shall be removed and properly diposed of.4. This effluent shall be pumped across a well vegetated area or through a silt fence prior to entering a watercourse.2.1 Sheet 2 of 2 12/03 Date: _________________ .Type 1 Construction Notes: 1. the pump shall be shut off while the structure drains down to the elevation of the wet storage.Standard Detail & Specifications Dewatering Basin . 7. Once the water level reaches the crest of the stone weir. The straw bales and/or geotextile fabric shall be inspected on a regular basis and shall be repaired or replaced once sediment prevents the structure from functioning as designed. Source: Adapted from VA ESC Handbook Symbol: Detail No. 2. DE-ESC-3. 2' min.Type 2 B 42' min. 2:1 Stone check dam 2' min.5:1 2:1 2' min. 2:1 Earth berm B A A Plan 2' R-4 riprap 1' DE #3 stone Flat 2:1 2:1 Stabilized outfall 2.Standard Detail & Specifications Dewatering Basin . Symbol: Detail No.5:1 15' min.4.5:1 1. Earth berm 2:1 2:1 1.5' 4" Type GS-I geotextile Section A-A Source: Adapted from DelDOT Stds. & Specs. 1.2 DWB-2 Sheet 1 of 2 12/03 Date: _________________ . 2' min. 3. 4. Length of the basin shall be based on the following formula: Top length (ft) = 26 + . Accumulated sediment shall be removed and disposed of in an approved disposal area when the basin is filled to within 18 inches of the crest of the wier.Standard Detail & Specifications Dewatering Basin . 6. 5.4. Pumping into the basin shall cease when the effluent from the basin becomes sedimentladen. length of 42 feet. Excess excavated material shall be stockpiled in accorcance with the approved plan and surface runoff shall be diverted around the basin. & Specs.5 feet as measured from the floor to the top of the berm. DWB-2 DE-ESC-3. 4' min. Basin shall have a min. If used in conjunction with the installation of a coffer dam. 1' 2.Type 2 6' min. Type GS-I geotextile 4" DE #3 stone Section B-B Construction Notes: 1. depth of 3. The outfall from the basin to the receiving waters shall be stabilized. Source: Adapted from DelDOT Stds.2 Sheet 2 of 2 12/03 Date: _________________ . width of 15 feet and a min.2. dewatering shall begin no sooner than 12 hours after coffer dam is completed in order to to allow settling of sediment produced during installation.01 x pump discharge (gpm) 2. a min. Symbol: Detail No. Ex.5' min. 2' min. grnd 2' min. Swale A Swale B Drainage Area 5 acres or less 5-10 acres Bottom of width of flow channel 4' 6' Depth of flow channel 1' 1' 3:1 or flatter 3:1 or flatter 0. 3. Swales collecting runoff from disturbed areas shall remain in place until the disturbed areas are permanently stabilized.1 12/03 .5% Min 20% Max Side slopes Grade 6 3. Intermediately across disturbed areas to shorten overland flow distances. To divert flows away from a disturbed area and to a stabilized area. Design Criteria Refer to the chart below for proper sizing criteria. 2. To direct sediment-laden water along the base of slopes to a trapping device.STANDARD AND SPECIFICATIONS FOR TEMPORARY SWALE Definition: A drainageway. temporary excavated Purpose: To prevent runoff from entering disturbed areas by intercepting and diverting it to a stabilized outlet or to intercept sedimentladen water and divert it to a sediment trapping device. To transport off-site flows across disturbed areas such as rights-of-way.1 .3.5% Min 20% Max 0. For drainage areas larger than 10 acres. Conditions Where Practice Applies: Temporary swales are constructed: 1. 4. refer to the Standard and Specifications for Channels. In highly erodible soils. Excavated portions of sediment traps shall have 1:1 or flatter slopes. use the next higher slope grade for type of stabilization. The flow channel shall be stabilized as outlined in the standard drawing. Outlet Temporary swales shall have an outlet that prevents additional erosion and reduces runoff velocity prior to discharge.Stabilization Stabilization shall be completed within 14 days of installation in accordance with the Standards and Specifications for Temporary Seeding and Mulching or Mulching only if not in seeding season.2 .3. as defined by the local approving agency.1 . All excavation operations shall be carried out in such a manner that erosion and water pollution shall be minimal. 6 12/03 3. Runoff shall be conveyed to a sediment trapping device such as a sediment trap or sediment basin until the drainage area above the swale is adequately stabilized. 5-3. b. 0. & Specs.FLOW DEPTH Type B (5-10 ac.Standard Detail & Specifications Temporary Swale Flow Flow Discharge to be directed to sediment trapping device (or stable outlet for clean water). Approved equivalents can be substituted for any of the above materials.0% Seed & straw mulch Seed & straw mulch 3 5.1-20% Seed with stab.0% 4 8. Adapted from MD Stds.0% 3. sod. blanket. blanket.3.) 4' 1' b . c.5% slope min.) 3:1 or Flatter b (min.1-8. for ESC Symbol: TS-(A/B)(1-4) Detail No.1-5.1 Sheet 1 of 2 12/03 Date: _________________ . DE #2 stone Lined R-4 riprap Type B Seed & straw mulch Seed using stab. sod. DE #2 stone Lined R-4 riprap Engineering design a. t Source: DE-ESC-3.) Type A (< 5 ac. Plan Existing ground d (min. Stone to be DE #2 inch stone in a layer at least 3 inches in thickness and be pressed into the soil with construction equipment.) 6' 1' Typical Section FLOW CHANNEL STABILIZATION CHART Stabilization Method Channel Grade Type A 1 2 0.BOTTOM WIDTH d . Riprap to be R-4 in a layer at least 8 inches thickness and pressed into the soil. Adapted from MD Stds. Fills shall be compacted by earth moving equipment. obstructions. All trees. Periodic inspection and required maintenance must be provided after each rain event. 2. All temporary swales shall have uninterrupted positive grade to an outlet with a minimum of erosion. 4. stumps. The swale shall be excavated or shaped to line. 8. and cross section as required to meet the criteria specified herein and be free of bank projections or other irreglarities which will impede normal flow.Standard Detail & Specifications Temporary Swale Construction Notes: 1. 7. brush. t Source: DE-ESC-3. and other objectionable material shall be removed and disposed of so as not to interfere with the proper functioning of the swale. All earth removed and not needed on construction shall be placed so that it will not interfere with the functioning of the swale.3. Diverted runoff from a disturbed area shall be conveyed to a sediment trapping device. 5. grade. Diverted runoff from an undisturbed area shall outlet directly into an undisturbed stabilized area at a non-erosive velocity. 6. for ESC Symbol: TS-(A/B)(1-4) Detail No.1 Sheet 2 of 2 12/03 Date: _________________ . 3. & Specs. 6 3. 2.1 12/03 . located in such a manner as to channel water to a desired location. Additional Criteria: 1. Purpose: To direct runoff to a sediment trapping device. adequate protection shall be provided to prevent erosion at the inflow point. The local approving agency may require a higher degree of stabilization for highly erodible soils. 4. The berms shall remain in place until the disturbed areas are permanently stabilized. For drainage areas > 10 acres refer to the Standard and Specifications for Diversion. Design Criteria: See Standard Detail for Type A or Type B temporary earth berms.3.STANDARD AND SPECIFICATIONS FOR TEMPORARY EARTH BERM Definition: A temporary earth dike or ridge of compacted soil. 3. thereby reducing the potential for erosion and off-site sedimentation. In situations where an earth dike is used to direct runoff into a sediment trap or basin. Conditions Where Practice Applies: Earth berms are often constructed across disturbed areas and around construction sites such as graded parking lots and subdivisions.2 . Stabilization of the dike shall be completed within 14 days of installation. Earth berms can also be used for diverting clean water away from disturbed areas. 3.2 .2 .This page left intentionally blank. 6 12/03 3. & Specs. or less ) 18" 24" 4' 8" DE-ESC-3.Standard Detail & Specifications Temporary Earth Berm Runoff cL Discharge to be directed to sediment trapping device (or stable outlet for clean water).BERM HEIGHT b . Flowline Limits of Contributing Area Plan b 3:1 or flatter 3:1 or flatter a Flow d Ex. t Source: Type A (5 ac. gnd c Excavate as needed to provide required flow width at design flow depth Section A-A a .FLOW DEPTH Adapted from MD Stds.) 36" 36" 6' 15" Symbol: TB-(A/B)(1-4) Detail No. for ESC Type B (5-10 ac.3.2 Sheet 1 of 2 12/03 Date: _________________ .FLOW WIDTH d .BERM WIDTH c . sod. blanket. in a layer at least 3 inches in thickness and be pressed into the soil with construction equipment. 7. Adapted from MD Stds. 6. Earth berms shall have an outlet that functions with a minimum of erosion.Standard Detail & Specifications Temporary Earth Berm FLOW CHANNEL STABILIZATION CHART Stabilization Method Channel Grade Type A Type B 1 2 0. & Specs.0% 3.3. Stabilization shall be: (a) In accordance with standard specifications for seed and straw mulch or straw mulch if not in seeding season. b.5-3. 2. All berms shall be compacted by earth-moving equipment.1-8. blanket. Stone to be 2 inch stone. DE-ESC-3. DE #2 stone Lined R-4 riprap Engineering design a. or recycled concrete equivalent. All berms shall have positive drainage to an outlet. (b) Flow channel as per the chart above.0% Seed & straw mulch Seed & straw mulch 3 5.1-20% Seed with stab.2 t Source: Sheet 2 of 2 12/03 Date: _________________ .1-5. Approved equivalents can be substituted for any of the above materials. Top width may be wider and side slopes may be flatter if desired to facilitate crossing construction traffic. for ESC Symbol: TB-(A/B)(1-4) Detail No. 3. sod. c. Periodic inspection and required maintenance must be provided after each rain event. Riprap to be 4-8 inches in a layer at least 8 inches thickness and pressed into the soil. Runoff shall be conveyed to a sediment trapping device such as a sediment trap or sediment basin where either the berm channel or the drainage area above the berm are not adequately stabilized. Construction Notes: 1. 4.0% 4 8. DE #2 stone Lined R-4 riprap Seed & straw mulch Seed using stab. Field location should be adjusted as needed to utilize a stabilized safe outlet. 5. a lined channel shall be specified.3 . Purpose: The purpose of a vegetated channel is to convey runoff without causing damage by erosion. The recommended methodology for stability design of vegetated channels is the tractive force method. Design Criteria 1. Vegetated channels may be specified for maximum design shear stresses less than 2 psf. but may also be used where the design criteria for temporary conveyance structures are exceeded and an engineered design is required. This allows the use of a single design procedure for most of the water conveyance practices contained in this handbook. Design Guide 1 outlines the procedures for this type of analysis. If the maximum design shear stress is equal to or greater than 2 psf. 24-hour NRCS Type II rainfall event or a higher frequency corresponding to the hazard involved. Refer to the Standard and Specifications for Stabilization Matting for additional guidance.Hydrology. Special situations which warrant a different methodology. Peak rates of runoff values used in determining the capacity requirements shall be based on USDA-NRCS methodology as outlined in TR 55 Urban Hydrology and/or TR 20 Project Formulation . They are generally considered to be permanent structures. Capacity The minimum capacity shall be that required to confine the peak rate of runoff expected from a 10-year frequency. Conditions Where Practice Applies Vegetated channels are used where added vegetative protection is needed to control erosion resulting from concentrated runoff. Stability All vegetated channels shall be stabilized with a temporary-type matting to accommodate a minimum flow depth of 1 foot. 2. such as the use of NRCS drainage curves for very flat landscapes.1 12/03 . This methodology is applicable to a wider range of lining types (including combination linings) and channel slopes than the allowable velocity method. 6 3.STANDARD AND SPECIFICATIONS FOR VEGETATED CHANNEL Definition: A natural or man-made channel of parabolic or trapezoidal cross-section that is below adjacent ground level and is stabilized by suitable vegetation. The flow channel is normally wide and shallow and conveys the runoff down the slope to a stable outlet. require prior approval from the Department.3. 4. grade stabilization structure.3.3.3.3. 4. drop structures. Outlets Each channel shall have a stable outlet. The design water surface elevation of a vegetated channel receiving water from diversions or other tributary channels shall be equal to or less than the design water surface elevation in the diversion or other tributary channels. In all cases. The cross-sectional area of the stone center or subsurface drain size to be provided shall be determined by using a flow rate of 0. Stabilization Vegetated channels shall be stabilized in accordance with Section 3. subsurface drain. Refer to Section 3. the outlet must discharge in such a manner as not to cause erosion. Where needed. it shall be handled by a stone center. When there is a base flow. Standard and Specifications for Vegetative Stabilization and Section 3.2 . The outlet may be another stabilized open channel. 6. Outlets shall be constructed and stabilized prior to the operation of the waterway.4.1 cfs/acre or by actual measurement of the maximum base flow. etc. or other suitable means since sustained wetness usually prevents adequate vegetative cover. parabolic. Standard and Specifications for Lined Channel and Section 3. or grade stabilization measures. or other means are provided to control meandering of low flows. Structural Measures In cases where grade or erosion problems exist.3 . 5. Standard and Specification for Chute for additional guidance. or trapezoidal. Cross Section The cross section shall be triangular.4. Stabilization Matting. 6 12/03 3.3.9. The top width of parabolic waterways shall not exceed 30 feet and the bottom width of trapezoidal waterways shall not exceed 15 feet unless multiple or divided waterways. special control measures may be needed such as linings. stone center. these measures must be supported by adequate design computations.6. Standard Detail & Specifications Vegetated Channel .3.Parabolic TW D 1/4 D 1/4 TW cL Typical Section (D esign) (Design) w 1' Stabilization matting (see separate detail for proper installation method) Typical Section (Stabilization) DATA Design discharge (Qd) Design topwidth (TW) Design depth (D) Design channel slope (s) Width of stabilization mat (w) Type of stabilization matting Delaware ESC Handbook Symbol: Detail No.1 Sheet 1 of 2 12/03 Date: _________________ .3. VC-P t Source: DE-ESC-3. 5. All earth removed and not needed in construction shall be spread or disposed of so that it will not interfere with the functioning of the waterway. b. stone center drain and/or subsurface drain. Delaware ESC Handbook Symbol: Detail No.3. Should groundwater or base flow conditions preclude the establishment of adequate vegetative stabilization throughout the entire design section. VC-P t Source: DE-ESC-3. 3. obstructions. and other objectionable material shall be removed and disposed of so as not to interfere with the proper functioning of the waterway. 2. temporary diversions or other means should be used to prevent water from entering the waterway during the establishment of the vegetation. grade. and be free of bank projections or other irregularities which will impede normal flow.1 Sheet 2 of 2 12/03 Date: _________________ . a.Standard Detail & Specifications Vegetated Channel . brush. Fills shall be compacted as needed to prevent unequal settlement that would cause damage in the waterway.3. It is recommended that. The channel shall be excavated or shaped to line. provisions shall be made through use of a lining material. Such practices shall be designed and constructed in accordance with the appropriate Standard(s) and Specifications and Standard Detail(s). and cross section as required to meet the criteria specified herein. stumps. All trees.Parabolic Construction Notes: 1. when conditions permit. 4. Stabilization shall be done in accordance with the appropriate Standard and Specifications for Vegetative Stabilization and Stabilization Matting. Channel . VC-T t Source: DE-ESC-3.Triang.2 Sheet 1 of 2 12/03 Date: _________________ .Standard Detail & Specifications Veg.3.3. TW Z B* 1 D * B = 0 for triangular section Typical Section (D esign) (Design) w 1' Stabilization matting (see separate detail for proper installation method) Typical Section (Stabilization) DATA Design discharge (Qd) Design topwidth (TW) Design depth (D) Design bottom width (B) Design sideslope (Z) Design channel slope (s) Width of stabilization mat (w) Type of stabilization matting Delaware ESC Handbook Symbol: Detail No./Trap. 4. brush. Channel . The channel shall be excavated or shaped to line. Such practices shall be designed and constructed in accordance with the appropriate Standard(s) and Specifications and Standard Detail(s)./Trap.3.Standard Detail & Specifications Veg. when conditions permit.2 Sheet 2 of 2 12/03 Date: _________________ . Construction Notes: 1. It is recommended that. 5. temporary diversions or other means should be used to prevent water from entering the waterway during the establishment of the vegetation. Delaware ESC Handbook Symbol: Detail No. stumps. Stabilization shall be done in accordance with the appropriate Standard and Specifications for Vegetative Stabilization and Stabilization Mat. 3. 2.3. and cross section as required to meet the criteria specified herein.Triang. obstructions. All earth removed and not needed in construction shall be spread or disposed of so that it will not interfere with the functioning of the waterway. a. Fills shall be compacted as needed to prevent unequal settlement that would cause damage in the waterway. grade. provisions shall be made through use of a lining material. and other objectionable material shall be removed and disposed of so as not to interfere with the proper functioning of the waterway. stone center drain and/or subsurface drain. VC-T t Source: DE-ESC-3. and be free of bank projections or other irregularities which will impede normal flow. All trees. b. Should groundwater or base flow conditions preclude the establishment of adequate vegetative stabilization throughout the entire design section. Standard Detail & Specifications Channel Pipe Drain TW cL Min.3.3. t Source: DE-ESC-3. 2' Cover D + d + Second Drain (as needed) Offset distance ( +) = 1/4 TW Typical Section DATA Offset distance ( + ) Drain installation depth (D) Drain diameter (d) Drain pipe material Adapted from IL Urban Manual Symbol: (VC/LC)(P/T) + PD Detail No.3 Sheet 1 of 2 12/03 Date: _________________ . A continuous 10-foot section of corrugated metal. The method of placement and bedding shall be as specified on the drawing. Where surface water is entering the system. Deformed. Adapted from IL Urban Manual Symbol: (VC/LC)(P/T) + PD Detail No. t Source: DE-ESC-3. or steel pipe without perforations shall be used at the outlet end of the line. No envelope material shall be used around the 10-foot section of pipe. 3. 2. 4. All subsurface drains shall be laid to a uniform line and covered with envelope material. Connections will be made with manufactured junctions comparable in strength with the specified pipe or tubing unless otherwise specified. Backfilling shall be done immediately after placement of the pipe.3. Place backfill in a manner that will not damage or displace the pipe. PVC. the pipe outlet section of the system shall contain a swing type trash and animal guard. or damaged pipe shall not be used.3 Sheet 2 of 2 12/03 Date: _________________ . 5. 6. The backfill material shall not contain rocks or other sharp objects. warped. cast iron. The upper end of each subsurface drain line shall be capped with a tight fitting cap of the same material as the conduit or other durable material unless connected to a structure. An animal guard shall be installed on the outlet end of the pipe. 7. The pipe or tubing shall be laid with the perforations down and oriented symmetrically about the vertical center line.3.Standard Detail & Specifications Channel Pipe Drain Construction Notes: 1. Envelope material shall consist of either filter cloth or DE #8 aggregate. 4 Sheet 1 of 1 12/03 Date: _________________ . t Source: DE-ESC-3.3.3.Standard Detail & Specifications Channel Stone Drain w t Filter fabric Typical Section (P ar abolic) (Par arabolic) w t Filter fabric Typical Section (T riangular) (Triangular) w t Filter fabric Typical Section (T (Trrapazoidal) Data Width of stone section (w) Thickness of stone (t) Median stone size (d50) Adapted from VA E&S Manual Symbol: VC/(P/T) + SD Detail No. Source: Symbol: Detail No. 12/03 Date: _________________ .Standard Detail & Specifications Channel Stone Drain This page left intentionally blank. STANDARD AND SPECIFICATIONS FOR LINED CHANNEL Definition: A channel with a lining of stone. 6 3. Conditions Where Practice Applies This practice applies where the following or similar conditions exist: 1. Soils are highly erosive or other soil and climate conditions preclude using vegetation. seepage. Scope: This standard applies to channels with linings of rock riprap. gabions or similar armor. Space limitations dictate a smaller channel cross section resulting in high velocities. 5. Steep grades. or to reinforced concrete channels. this standard shall also apply to turf reinforcement mats and other synthetic linings which are considered permanent in nature. 3. Neither does it apply to relatively short lined channels on very steep slopes which fall under the scope of the Standard and Specification for Chute. The earth above the permanent lining may be vegetated or otherwise protected.3. vegetated channels with stone centers (small lined sections to carry prolonged low flows). It does not apply to irrigation ditches.1 12/03 . prolonged base flow. wetness. The location is such that damage from use by people or animals precludes the use of vegetated waterways or outlets. 4.4 . Concentrated runoff is such that a lining is required to control erosion. The lined section extends up the side slopes to the designed depth. 2. or piping would cause erosion. In addition. or other permanent material. Purpose: To provide for the conveyance of concentrated runoff without damage from erosion or flooding where a vegetated channel alone would not be stable. canal linings. .. parabolic..... 4....Vertical 6.. Cross Section The cross section shall be triangular.. 3. Vegetated channels may be specified for maximum design shear stresses less than 2 psf... mattress 7...Design Criteria 1....The minimum lining thickness shall be as follows: Rock riprap. This allows the use of a single design procedure for most of the water conveyance practices contained in this handbook. Special situations which warrant a different methodology require approval from the Department.Hydrology.................1...... Freeboard The minimum freeboard for lined channels shall be 0. If the maximum design shear stress is equal to or greater than 2 psf... Lining Thickness ... 24-hour NRCS Type II rainfall event or a higher frequency corresponding to the hazard involved... This methodology is applicable to a wider range of lining types (including combination linings) and channel slopes than the allowable velocity method. 6 12/03 3. Design Guide 1 outlines the procedures for this type of analysis.... drop structures. Stability The recommended methodology for stability design of conveyance channels is the tractive force method. and energy dissipators shall meet the hydraulic and structural requirements of the site....25 feet above the design high water in areas where erosionresistant vegetation cannot be grown adjacent to the lining on the side slopes. Related Structures Side inlets. or trapezoidal. 5.. 2...2 to 1 Gabions....3.9 in....... a lined channel shall be specified..4 . Capacity The minimum capacity shall be that required to confine the peak rate of runoff expected from a 10-year frequency.. No freeboard is required where good vegetation can be grown and is maintained... Peak rates of runoff values used in determining the capacity requirements shall be based on USDA-NRCS methodology as outlined in TR 55 Urban Hydrology and/or TR 20 Project Formulation ...... Side Slope The steepest permissible side slopes.....5 x maximum stone size Gabion.. horizontal to vertical will be as follows: Rock riprap.....2 ... The fabric shall meet the minimum properties standards as specified in Appendix A-3. Outlets Each lined channel shall have a stable outlet. Vegetation next to the lining should be maintained in good condition to prevent scouring if out-of-bank flow occurs. 6 3. Riprap shall be composed of a well graded mixture of stone sizes so that 50 percent of the pieces. 10.3 12/03 . Gabions shall be installed according to manufacturers recommendations.8. grade stabilization structure. Gabions shall be filled with R-3 stone. 11. Maintenance Inspect channels on a regular basis and after major rainfall events.3. by weight. the outlet must discharge in such a manner as not to cause erosion.4 . 9. The outlet may be another channel. and thawing. and lid can be assembled at the site into a rectangular basket of similar size. water. In all cases. freezing. Lined channels with velocities exceeding critical shall discharge into an energy dissipator to reduce velocity to less than critical. Gabion Baskets Gabions shall be fabricated in such a manner that the sides. etc. Outlets shall be constructed and stabilized prior to the operation of the lined channels. ends. are larger than the d50 size determined in the design. Rock riprap Stone used for riprap or gabions shall be dense and hard enough to withstand exposure to air. Geotextile fabric A Type GS-I geotextile fabric shall be placed beneath all riprap and gabions. Pay special attention to inlet and outlet sections and other points where concentrated flow enters the channel. and to a velocity the downstream soil and vegetative conditions will be stable. 4 .4 .3. 6 12/03 3.This page left intentionally blank. 3.. paving block. specify basket dimensions to be used. LC/P t Source: *For gabions & reno mattresses. etc. gabion mattress. etc.1 Sheet 1 of 2 12/03 Date: _________________ . DE-ESC-3.Parabolic TW D 1/4 D 1/4 TW cL Typical Section (D esign) (Design) w 4" d t 6" Type GS-I geotextile Lining of loose riprap.Standard Detail & Specifications Lined Channel . Typical Section (Lining) DATA Design discharge (Qd) Design topwidth (TW) Design depth (D) Width of lining (w)* Lining flow depth (d) Thickness of lining (t)* Median stone size (d50)** Adapted from VA ESC Manual **For paving block.4. Symbol: Detail No. specify size to be used. grade.1 Sheet 2 of 2 12/03 Date: _________________ . Lining shall be installed to the design dimensions specified on the approved plan. 6. and cross section as required to meet the criteria specified herein. density. and other objectionable material shall be removed and disposed of so as not to interfere with the proper functioning of the waterway. Stabilization shall be done according to the appropriate Standard and Specifications for Vegetative Stabilization. strength.Parabolic Construction Notes: 1. All earth removed and not needed in construction shall be spread or disposed of so that it will not interfere with the functioning of the waterway. 2. The channel shall be excavated or shaped to line. 5. or other criterion so specified. Adapted from VA ESC Manual Symbol: Detail No.Standard Detail & Specifications Lined Channel . All preengineered linings shall be installed in acordance with the manufacturer's recommendations. 3. LC/P t Source: DE-ESC-3. obstructions. 7. brush. and be free of bank projections or other irregularities which will impede normal flow. Lining material shall be as specified on the approved plans with respect to dimension. All trees. Type GS-I geotextile shall be used on all installations unless specifically approved otherwise. stumps.4.3. 4. Fills shall be compacted as needed to prevent unequal settlement that would cause damage in the waterway. 4. etc. specify basket dimensions to be used. specify size to be used. DE-ESC-3. Symbol: Detail No. LC/T t Source: *For gabions & reno mattresses.2 Sheet 1 of 2 12/03 Date: _________________ . Typical Section (Lining) DATA Design discharge (Qd) Design topwidth (TW) Design depth (D) Design bottom width (B) Design sideslope (Z) Width of lining (w)* Lining flow depth (d) Thickness of lining (t)* Median stone size (d50)** Adapted from VA ESC Manual **For paving block.Triang. etc.3.. paving block. gabion mattress./Trap.Standard Detail & Specifications Lined Channel . TW Z B* 1 D * B = 0 for triangular section Typical Section (D esign) (Design) w 4" d t 6" Type GS-I geotextile Lining of loose riprap. All preengineered linings shall be installed in acordance with the manufacturer's recommendations. or other criterion so specified. Type GS-I geotextile shall be used on all installations unless specifically approved otherwise. Fills shall be compacted as needed to prevent unequal settlement that would cause damage in the waterway. Lining material shall be as specified on the approved plans with respect to dimension.Standard Detail & Specifications Lined Channel . Construction Notes: 1.2 Sheet 2 of 2 12/03 Date: _________________ . brush. 4. strength.4. density.3. Lining shall be installed to the design dimensions specified on the approved plan. Adapted from VA ESC Manual Symbol: Detail No. Stabilization shall be done according to the appropriate Standard and Specifications for Vegetative Stabilization. stumps. and cross section as required to meet the criteria specified herein. 3. All earth removed and not needed in construction shall be spread or disposed of so that it will not interfere with the functioning of the waterway. 2. and other objectionable material shall be removed and disposed of so as not to interfere with the proper functioning of the waterway. 7. The channel shall be excavated or shaped to line. and be free of bank projections or other irregularities which will impede normal flow. grade. LC/T t Source: DE-ESC-3. All trees.Triang. 5. obstructions./Trap. 6. 5 . Runoff from higher areas is or has potential for damaging properties. Diversions are to be used only below stabilized or protected areas. seep planes (when seepage is a problem). Diversions are used where: 1.3. Purpose: The purpose of a diversion is to intercept and convey runoff to stable outlets at non-erosive velocities. 3. Design Criteria Diversions are essentially channels which are constructed across a slope. Location Diversion location shall be determined by considering outlet conditions. and the development layout. Construction of diversions shall be in compliance with state drainage and water laws. soil type. Additional design criteria specific to diversions are as follows: 1. Surface and/or shallow subsurface flow is damaging sloping upland. or interfering with or preventing the establishment of vegetation on lower areas. causing erosion.STANDARD AND SPECIFICATIONS FOR DIVERSION Definition: A drainage way of parabolic or trapezoidal cross-section with a supporting ridge on the lower side that is constructed across the slope. but may also be used where the design criteria for temporary earth dikes are exceeded and an engineered design is required. This requires a berm on the downslope side to prevent flow from "kicking out" of the channel. 2. The design for capacity and stability of the channel itself shall be in accordance with the Standard and Specification for Vegetated or Lined Channels. length of slope. land use. 6 3. topography. Avoid establishment on slopes greater than fifteen percent.1 12/03 . The length of slope needs to be reduced so that soil loss will be reduced to a minimum. Diversions should be used with caution on soils subject to slippage. Conditions Where Practice Applies Diversions are generally considered to be permanent structures. parking lots. The berm shall have a minimum width of four feet at the design water elevation. the peak discharge from a ten-year frequency rainfall event with freeboard of not less than 0. 6. The side slopes shall not be steeper than 3:1 and shall be flat enough to insure ease of maintenance of the diversion and its protective vegetative cover. 4. Outlets Each diversion must have an adequate outlet. grade stabilization structure.5 .5 foot freeboard and a 10% settlement factor shall be provided. industrial buildings. and those designed to function in connection with other structures. 3.5 of a foot. Stabilization Diversions shall be stabilized in accordance with the appropriate Standard and Specifications for Vegetative Stabilization. 5. a minimum of 0. 6 12/03 3. roads. schools.3. Cross Section The diversion channel shall be parabolic or trapezoidal in shape.2 . The design elevation of the water surface in the diversion shall not be lower than the design elevation of the water surface in the outlet at their junction when both are operating at design flow. The diversion shall be designed to have stable side slopes.2. as a minimum. stable watercourse. The outlet may be a stable channel. or pipe outlet. to insure establishment of vegetative cover in the outlet channel. Velocity and Grade The design velocity for the specified method of stabilization will determine the maximum grade. vegetated or paved area. Diversions designed to protect homes. and comparable high risk areas. shall have sufficient capacity to carry peak runoff expected from a storm frequency consistent with the hazard involved. The use of diversions below high sediment producing areas is not acceptable unless land treatment practices or structural measures designed to prevent damaging accumulations of sediment in the channels are installed with or before the diversions. Vegetated outlets shall be installed before diversion construction. Capacity A diversion shall have the capacity to carry. if needed. Maximum permissible velocities of flow for the stated conditions of stabilization shall be as determined in accordance with the Standard and Specifications for Vegetated or Lined Channels. In all cases the outlet must convey runoff to a point where outflow will not cause damage. ½ 10% Settlement Min. (See separate detail. 0. tt Source: DE-ESC-3. 0.(P/T) D Detail No. 0.5' freeboard ¾ 3:1 or fla tte r * Typical Section (P ar abolic) (Par arabolic) ½ 10% Settlement 4' Min.5' freeboard * Typical Section (T riangular) (Triangular) *Flow section to be designed and constructed in accordance with Standard & Specification for Vegetated Channel or Lined Channel.) Adapted from VA ESC Handbook Symbol: (VC/LC). ¾ 3:1 or fla tte r Min.3.5' freeboard * Typical Section (T (Trrapazoidal) ½ 10% Settlement 4' Min. ¾ 3:1 or fla tte r Min.5 Sheet 1 of 2 12/03 Date: _________________ .Standard Detail & Specifications Diversion 4' Min. brush. 2. obstructions. All trees. Stabilization shall be done according to the appropriate Standard and Specifications for Vegetative Stabilization. The diversion shall be excavated or shaped to line. 4. 6. and other objectionable material shall be removed and disposed of so as not to interfere with the proper functioning of the diversion. 5. grade. All earth removed and not needed in construction shall be spread or disposed of so that it will not interfere with the functioning of the diversion. tt Source: DE-ESC-3.Standard Detail & Specifications Diversion Construction Notes 1.5 Sheet 2 of 2 12/03 Date: _________________ . and cross section as required to meet the criteria specified herein.(P/T) D Detail No. Flow section shall be installed in accordance with the Standard and Specifications for Vegetated Channel or Lined Channel.3. and be free of irregularities which will impede normal flow. Adapted from VA ESC Handbook Symbol: (VC/LC). as appropriate. Fills shall be compacted as needed to prevent unequal settlement that would cause damage in the completed diversion. stumps. 3. They should not be used in a free flowing stream. care should be taken to remove all the stone when the check dam is removed. Design Criteria Check dam spacing is based on the following equation: X = Y / S Where: X = Max. cannot receive a non-erodible lining but still need some protection to reduce erosion.1 6/05 .3. Temporary swales or channels which. thereby reducing erosion of the swale or channel. Check dams may be installed as temporary structures during the construction phase or may remain as permanent stormwater management structures. Planning Considerations The location of check dams shall provide for maximum velocity reduction. 2. The check dams should be placed in reasonably straight sections of the swale or channel in order to minimize the potential for erosion due to curves in the swale or channel. check dam spacing (ft) Y = Check dam height (ft) S = Channel slope (ft/ft) 6 3. Some specific applications include: 1. Although this practice may also trap small amounts of sediment generated in the swale or channel. If temporary check dams are used in grass-lined swales or channels which will be mowed. Either temporary or permanent swales or channels which need protection during the establishment of grass linings. because of their short length of service. Purpose: To reduce the velocity of concentrated flows. it is not intended to be a sediment trapping practice and should not be used as such.6 .STANDARD AND SPECIFICATIONS FOR CHECK DAMS Definition: Small dams constructed across a swale or channel which act as grade control structures. 3. Permanent swales or channels which for some reason cannot receive a permanent non-erodible lining for an extended period of time. Conditions Where Practice Applies This practice is limited for use in small open channels where it is necessary to slow the velocity of flows in order to prevent erosion. including wood.200 S = 0. In permanent structures. Check dams are not practical on slopes greater than 10%.0 Check Dam Height.6 .0 1.01 Check Dam Spacing. 6 6/05 3. should be explored for these situations. temporary check dams may be removed when the grass has matured sufficiently to protect the swale or channel. etc.10 0 1. The area beneath the check dams should be seeded and mulched immediately after they are removed.3.06 S = 0. Maintenance Check dams should be checked for sediment accumulation after each significant rainfall.6a Check Dam Spacing Chart ( X = Y/S ) Figure 3. should be used for slopes less than 1.6a can be used to solve the check dam spacing equation within the range of typical designs. However. articulated block.0%. check dams should be removed and the ditch filled in when it is no longer needed. In the case of grass-lined ditches.015 S = 0.2 . such as chutes or lined channels.04 50 S = 0. Removal In temporary swales and channels. Sediment should be removed when it reaches one half of the original height or before.03 S = 0.5 2. A maximum spacing of 200 ft. temporary check dams may be removed when a permanent lining can be installed. Materials Check dams may be constructed from a variety of materials. most applications in erosion and sediment control will make use of stone and/or riprap. Alternative designs.02 100 S = 0.3. Y (ft) Figure 3. concrete.3. X (ft) 150 S = 0. 12" S 1' thick layer of DE No. 57 stone Y X Profile L (Min. SCD DE-ESC-3.6 Sheet 1 of 2 6/05 Date: _________________ . for ESC L (Min. 4') Min. 4') NOTE: Angle ends upstream Symbol: Detail No. 6" Y (Min.3. 12") Geotextile fabric for permanent check dams Section DATA X Slope (S) Spacing (X) Length of weir (L) Height of stone (Y) Flow Plan Source: Adapted from MD Stds. & Specs.Standard Detail & Specifications Stone Check Dam R-4 Riprap Min. 3.6 SCD Sheet 2 of 2 6/05 Date: _________________ . The maximum height of the check dam at the center of the weir must not exceed two (2) feet. Temporary Swale. for ESC Symbol: Detail No. or Diversions. (See Standard & Specifications for Check Dams for design chart. The top of the check dam shall be constructed so that the center is approximately 6" lower than the outer edges.) Source: Adapted from MD Stds. The check dam shall be constructed of 4" to 8" riprap. forming a weir that the water can flow across. 3.Standard Detail & Specifications Stone Check Dam Construction Notes: 1. 5. 2. DE-ESC-3. Vegetated Channel. Maximum spacing between dams should be the distance in the channel where the toe of the upstream dam is at the same elevation as the top of the downstream dam. 4. The riprap shall be placed so that it completely covers the width of the channel. & Specs. Swales and channels shall be prepared in accordance with the construction specifications described in the Standards and Specifications for Temporary Berm. The minimum length of weir shall be 4'. Improve the environment for vegetative growth by regulating the water table and groundwater flow into channels and other BMP's.STANDARD AND SPECIFICATIONS FOR SUBSURFACE DRAIN Definition: A perforated conduit or pipe installed below the ground surface which intercepts. 6. subsurface drainage generally falls into two classes: relief and interception drainage. Improve dewatering of sediment in sediment basins. This standard does not apply to storm drainage systems or foundation drains. 8. 9.7 . Provide subsurface drainage for dry stormwater management structures. From a functional standpoint. 2. either by gravity flow or by pumping. etc. 7.1 12/03 . Purpose:A subsurface drain may serve one or more of the following purposes: 1.3. Replace existing subsurface drains that are interrupted or destroyed by construction operations. Remove surface runoff. 5.) Conditions Where Practice Applies Subsurface drains are used in areas having a high water table or where subsurface drainage is required. Relieve artesian pressures. An outlet for the drainage system shall be available. Relief drainage is used 6 3. retaining walls. 4. The outlet shall be adequate for the quantity of water to be discharged without causing damage above or below the point of discharge and shall comply with all state and local laws. Design Criteria The design and installation shall be based on adequate surveys and on-site soils investigations. The soil shall have enough depth and permeability to permit installation of an effective system. 3. (See Standard and Specifications for SedimentBasins. Provide internal drainage behind bulkheads. Provide internal drainage of slopes to improve their stability and reduce erosion. collects and conveys excess water to a suitable outlet. Intercept and prevent water movement into a wet area. The minimum depth of cover may be reduced to 15 inches where it is not possible to attain the 24 inch depth and where the drain is not subject to equipment loading or frost action. Generally.2 . Typical layouts for subsurface drainage collection systems are shown in Figure 3. they may be used for determining capacity. Where subsurface drainage is to be uniform over an area through a systematic pattern of relief drains. a minimum inflow rate of 0.7 . Where subsurface drainage is to be by random interceptor system or for channel drains. If actual field tests and measurements of flow amounts are available. As such. In some situations. For interceptor subsurface drains on sloping land. The Standard Detail for Channel Drain may be used where subsurface drainage is needed to establish/maintain vegetative cover in a channel under high water table and/or groundwater inflow conditions. one on either side of the channel centerline. Depth and Spacing The minimum depth of cover of subsurface drains shall be 24 inches where possible. a drainage coefficient of 1 inch to be removed in 24 hours shall be used.to lower a high water table which is generally flat or of very low gradient. Required Capacity of Drains The required capacity shall be determined by one or more of the following: 1. the drain should be offset from the channel centerline at least one-fourth of the top width distance. and lower the flowline of the water in the problem area and is particularly applicable for controlling seeps and springs.5 cfs per 1.7e is for PVC and other smooth-type pipe. Roots from some types of vegetation can plug drains as the drains get closer to the surface.3. Size of Subsurface Drain The size of subsurface drains shall be determined from the Drain Charts found at the end of this section. Additional design capacity must be provided if surface water is allowed to enter the system. the depth of installation of the drains and degree of drainage required.7d is for corrugated plastic tubing and Figure 3. Interception drainage is used to intercept. The minimum diameter for a subsurface drain shall be four (4) inches.000 feet of line shall be used to determine the required capacity. Figure 3.3. The spacing of drain laterals in a collection system will be dependent on the permeability of the soil. increase the inflow rate as follows: Land Slopes Increase Inflow Rate By 2-5 percent 5-12 percent Over 12 percent 10 percent 20 percent 30 percent 3. reduce the flow. Such systems shall have a site specific plan showing the appropriate details. relief drains should be located through or near the center of the problem area and should drain in the same general direction as the slope. Interceptor drains should be located on the uphill side of the problem area and should be installed across the slope and drain to the side of the slope. drains installed 36 inches deep and 6 12/03 3. For channel drain installations. it may be necessary to install two drains.7a.3.3. (See Drain Charts) 2. 7a Typical Subsurface Drain Layout Pattens (Source: NRCS.7 . 16) 6 3.Figure 3. Sect. National Engineering Handbook.3.3.3 12/03 . The interceptor drain spacing equation is: Le = ki ( d e − d w + w2 ) q Where: Le = distance downslope from the drain to the point where the water table is at the desired depth after drainage (ft) k = avg. Where the gradient is less than this the drain functions more like a relief drain and spacing may be computed using the ellipse equation.1 to 0./hr) de = effective depth of the drain (ft) dw = desired min.spaced 50 feet center-to-center will be adequate. The variables used in the equation for interceptor drain spacing are shown graphically in Figure 3. another iteration is indicated.3. Limitations in its use are contained in Section 16 of NRCS's National Engineering Handbook. 6 12/03 3. Le and w2 interdependent variables.7 . this should be verified using the following design methodologies. empirical equations have been developed for the required spacing based on the assumption that the hydraulic gradient of the undisturbed water table is in the range of 0.7b./hr) i = hydraulic gradient of the water table prior to drainage (ft/ft) q = drainage coefficient (in./hr) 2. hydraulic conductivity or permeability (in. However. is as follows: 4k ( M 2 + AM ) S= q Where: S = drain spacing (ft) k = avg. Interceptor drains When it is necessary to install more than one interceptor drain. the solution requires an iterative process in which an estimated value of w2 is used to compute a trial value of Le. The variables used in the equation are shown graphically in Figure 3. 1. itself.3 ft/ft or greater. The equation. depth to water table after drainage (ft) w2 = distance from the ground surface to the water surface table. after drawdown.7c. at the distance Le downslope from the drain (ft) In the equation above. Therefore.3. If the actual value of w2 at distance Le is outside tolerable limits. Relief drains The ellipse equation is used extensively in the Mid-Atlantic region to determine proper spacing of relief drains./hr) M = vertical distance. before drainage. hydraulic conductivity or permeability (in.3.4 . of water table above drain at mid-point between lines (ft) A = depth of barrier below drain (ft) q = drainage coefficient or rate of water removal (in. Figure 3.3.7b Terminology used in spacing of relief drains. Source: VA E&S Handbook Figure 3.3.7c Terminology used in spacing of interceptor drains. Source: VA E&S Handbook 6 3.3.7 - 5 12/03 Minimum Velocity and Grade The minimum grade for subsurface drains shall be 0.10 percent. Where surface water enters the system a velocity of not less than 2 feet per second shall be used to establish the minimum grades. Provisions shall be made for preventing debris or sediment from entering the system by means of filters or collection and periodic removal of sediment from installed traps. Materials for Subsurface Drains Acceptable subsurface drain materials include perforated, continuous closed joint conduits of corrugated plastic, corrugated concrete, corrugated metal, bituminized fiber and polyvinyl chloride. The conduit shall meet strength and durability requirements of the site. Loading The allowable loads on subsurface drain conduits shall be based on the trench and bedding conditions specified for the job. A factor of safety of not less than 1.5 shall be used in computing the maximum allowable depth of cover for a particular type of conduit. Envelopes and Envelope Materials Envelopes shall be used around subsurface drains for proper bedding and to provide better flow into the conduit. Not less than three inches of envelope material shall be used for sand-gravel envelopes. Where necessary to improve the flow of groundwater into the conduit, more envelope material may be required. Envelope material shall be placed to the height of the uppermost seepage strata. Behind bulkheads and retaining walls, it shall go to within twelve inches of the top of the structure. This standard does not cover the design of filter materials where needed. Envelope materials shall consist of either filter cloth or DE #8 aggregate. The filter cloth envelope can be either woven or nonwoven monofilament yarns and shall have a sieve opening ranging from 40-80. The envelope shall be place in such a manner that once the conduit is installed, it shall completely encase the conduit. The conduit shall be placed and bedded in a sand-gravel envelope. A minimum of three inches depth of envelope materials shall be placed on the bottom of a conventional trench. The conduit shall be placed on this and the trench completely filled with envelope material to minimum depth of 3 inches above the conduit. Soft or yielding soils under the drain shall be stabilized where required and lines protected from settlement by adding gravel or other suitable material to the trench, by placing the conduit on a plank or other rigid support, or by using long sections of perforated or watertight pipe with adequate strength to insure satisfactory subsurface drain performance. Use of Heavy Duty Corrugated Plastic Drainage Tubing Heavy duty corrugated plastic drainage tubing shall be specified where rocky or gravelly soils are expected to be 6 12/03 3.3.7 - 6 encountered during installation operations. The quality of tubing will also be specified when cover over this tubing is expected to exceed 24 inches for 4, 5, 6, or 8-inch tubing. Larger size tubing designs will be handled on an case by case basis. Auxiliary Structure and Subsurface Drain Protection The outlet shall be protected against erosion, undermining of the conduit, damaging periods of submergence and entry of rodents or other animals into the subsurface drain. An animal guard shall be installed on the outlet end of the pipe. A continuous 10-foot section of corrugated metal, cast iron, PVC, or steel pipe without perforations shall be used at the outlet end of the line and shall outlet 1.0 foot above the normal elevation of low flow in the outlet ditch or mean high tide in tidal areas. No envelope material shall be used around the 10-foot section of pipe. Two-thirds of the pipe shall be buried. Conduits under roadways and embankments shall be watertight and designed to withstand the expected loads. Where surface water enters subsurface drains, inlets shall be designed to exclude debris and prevent sediment from entering the conduit. Lines flowing under pressure shall be designed to withstand the resulting pressures and velocity of flow. Surface waterways shall be used where feasible. The upper end of each subsurface drain line shall be capped with a tight fitting cap of the same material as the conduit or other durable material unless connected to a structure. 6 3.3.7 - 7 12/03 Figure 3.3.7d Drainage chart for corrugated plastic tubing Source: NRCS, Engineering Field Manual, Chapter 14 6 12/03 3.3.7 - 8 Figure 3.3.7e Drainage chart for clay, concrete and PVC pipe Source: NRCS, Engineering Field Manual, Chapter 14 6 3.3.7 - 9 12/03 This page left intentionally blank. 6 12/03 3.3.7 - 10 STANDARD AND SPECIFICATIONS FOR PIPE SLOPE DRAIN Definition: A temporary pipe structure placed from the top of a slope to the bottom of a slope. Purpose: To convey surface runoff down slopes without causing erosion. Conditions Where Practice Applies: Used where concentrated flow of surface runoff must be conveyed down a slope in order to prevent erosion. The maximum allowable drainage area shall be 5 acres. Design Criteria for Pipe Drop Structure: Size PSD-12 PSD-18 PSD-21 PSD-24 PSD-30 Pipe/Tubing Diameter D (in) Maximum Drainage Area (Acres) 12 18 21 24 30 0.5 1.5 2.5 3.5 5.0 Outlet The pipe drop structure shall outlet into a sediment trapping device when the drainage area is disturbed. A riprap apron with filter cloth shall be installed below the pipe outlet where clean water is being discharged into a stabilized area. Where a pipe drop structure outlets into a sediment trapping device, it shall discharge at the riser crest or weir elevation. 6 3.3.8 - 1 12/03 This page left intentionally blank. 6 12/03 3.3.8 - 2 Standard Detail & Specifications Pipe Slope Drain Berm 4' min. Hold-down stakes 3 D 1 H* 10' spacing max. 1 Corrugated plastic tubing Stabilized outlet Z Flared end section Toe plate (* Min. H = D X 2) 4' min. level section Profile D DATA Contributing D.A. 6D Height of Berm (H) 3D + 2' Stabilized Outlet D etail Detail Adapted from IL Urban Manual Symbol: Detail No. PSD-(Dia.) t Source: DE-ESC-3.3.8 Sheet 1 of 2 12/03 Date: _________________ Standard Detail & Specifications Pipe Slope Drain Construction Notes: 1. The top of the earth berm over the inlet pipe and those berms carrying water to the pipe shall be at least 2X the pipe diameter at all points. Earth berm side slopes steeper than 3:1 shall have stabilization blanket applied. 2. Flexible tubing is preferred. (Alternate materials must receive prior approval.) All connections shall be made with watertight connecting bands. 3. A flared end section shall be attached to the inlet end of the pipe with a watertight connection. 4. The flexible tubing shall be securely anchored to the slope by hold-down stakes spaced 10' on centers. In no case shall less than two (2) anchors be provided. 5. A riprap apron shall be provided at the outlet. This shall consist of R-4 riprap placed as shown on the Standard Detail. 6. The soil around and under the inlet pipe and entrance section shall be hand tamped in 4" increments to the top of the earth dike. 7. Follow-up inspection and any needed maintenance shall be performed after each storm. MAXIMUM DRAINAGE AREA: 5 ACRES Adapted from IL Urban Manual Symbol: Detail No. DE-ESC-3.3.8 PSD-(Dia.) t Source: Sheet 2 of 2 12/03 Date: _________________ STANDARD AND SPECIFICATIONS FOR CHUTE Definition: A structure used to control the grade and head cutting in a channel. Purpose: To stabilize the grade and control erosion in a channel to prevent the formation or advance of gullies. Conditions Where Practice Applies: In areas where the concentration and flow velocity require structures to safely convey water from a higher elevation to a lower elevation in a relatively short, steep channel section. Flow coming into a chute is typically contained in a channel. The chute itself may discharge to the same channel at a lower elevation, act as a side-inlet to another channel, or discharge into a body of water such as a sediment trap, pond or stream. Scope: This standard shall be limited to chutes which fall under the design criteria stated below. For situations which exceed these criteria, the chute shall have a site-specific design in accordance with the procedures contained in the NRCS National Engineering Handbook, Section 14 or similar guidance. Design Criteria: Chutes are essentially channels on very steep slopes. Because of this, the forces of momentum, gravity, and friction play a more important role in their stability as compared to a channel on a mild slope. A chute under this standard and specification having a flexible lining shall be designed in accordance with the tractive force method. Design Guide 1 outlines the recommended procedure for this methodology. The hydraulic design of the chute shall be based on the design discharge of the incoming channel. The configuration of the chute itself shall include a transition section for both the incoming and outgoing flow. Outlet: The outlet is the most critical component of a chute since it is subjected to the maximum forces associated with the flow. As such, the designer should give serious consideration to providing an energy dissipating structure, such as a stilling basin, at the outlet of the chute. As a minimum, an armored transition section must be provided to protect against impact and scour. The armoring should extend far enough to ensure the flow can transition to the receiving channel or water body in a non-erosive manner. Maintenance: Periodic visual inspection is crucial for chutes since a failure can lead to severe gully erosion and head-cutting in a very short time. The chute should be checked for signs of failure in the lining as well as evidence of scour between the lining and vegetated areas. If found, repairs should be made immediately. 6 3.3.9 - 1 12/03 This page left intentionally blank. 6 12/03 3.3.9 - 2 Standard Detail & Specifications Riprap Chute Z 1 1 Z 10' min. 3' min. S 10' min. DATA Design discharge (Q) Bottom width (b) Side slope (Z) Depth (d) Riprap size (d50) Riprap thickness (T) Slope (s) Perspectiv erspectivee d (1' min.) 1 1 Z Z b (3' min.) Type GS-I geotextile fabric T (12" min.) Typical Section Adapted from MD Stds. & Specs. for ESC Symbol: Detail No. RRC DE-ESC-3.3.9.1 t Source: Sheet 1 of 2 12/03 Date: _________________ 4.3. RRC t Source: DE-ESC-3. & Specs. Adapted from MD Stds. with a minimum of 12".1 Sheet 2 of 2 12/03 Date: _________________ .9. All riprap shall be underlain with Type GS-I geotextile fabric. Entrance and exit aprons shall be provided as transition areas. Riprap chutes shall have a trapezoidal cross section with side slopes of 2:1 or flatter. 3. 2. The riprap layer thickness shall be 1. for ESC Symbol: Detail No. Aprons shall be a minimum of 10' in length.Standard Detail & Specifications Riprap Chute Construction Notes: 1.5 X Dmax. Minimum flow depth shall be 1' with a minimum bottom width of 3'. 2 Sheet 1 of 2 12/03 Date: _________________ . & Specs. min DATA Design discharge (Q) Bottom width (b) Depth (d) Slope (s) Perspectiv erspectivee Entrance apron 3' min.Standard Detail & Specifications Gabion Mattress Chute d (1' min.9. gnd 9" 3' min.) 3 3' min .) NOTE: Use 9' x 3' x 9" baskets 3' . GMC t Source: DE-ESC-3. Exit apron Type GS-I geotextile fabric Profile Adapted from MD Stds. s 1' 1' NOTE: Key into exist.3. 1 1 3 3' min. b (3' min. for ESC Symbol: Detail No. 2 Sheet 2 of 2 12/03 Date: _________________ . The top mattress shall be keyed into existing ground a minimum of 1' in depth.9.Standard Detail & Specifications Gabion Mattress Chute Construction Notes: 1. 3. Adapted from MD Stds.3. GMC t Source: DE-ESC-3. Aprons shall be a minimum of 3' in length. Gabion mattress chutes shall be constructed of 9' x 3' x 9" gabion baskets forming a trapezoidal cross section. & Specs. Entrance and exit aprons shall be provided as transition areas. for ESC Symbol: Detail No. 2. All baskets shall be underlain with Type GS-I geotextile fabric. Apron Size The apron length and width shall be determined from the curves according to the tailwater condition: Minimum Tailwater . Tailwater depth The depth of tailwater immediately below the pipe outlet must be determined for the design capacity of the pipe. dry storm water ponds.10a Maximum Tailwater . conduits and channels. conduits and channels are sufficient to erode the next downstream reach.1 12/03 . Such situations require the use of chutes or other grade stabilization structures.3. This applies to: 1. New channels constructed as outlets for culverts and conduits. Pipes which outlet onto flat areas with no defined channel may be assumed to have a Minimum Tailwater Condition.3.Use Figure 3. If the tailwater depth is less than half the diameter of the outlet pipe and the receiving stream is wide enough to accept divergence of the flow. The design of rock outlet protection depends entirely on the location. it shall be classified as a Minimum Tailwater Condition.STANDARD AND SPECIFICATIONS FOR RIPRAP OUTLET PROTECTION Definition: A section of rock protection placed at the outlet end of culverts. Design Criteria Riprap outlet protection designed under this standard shall have a minimum d50 size of 6".10 . 3. Purpose: To reduce the velocity and energy of water.3.10b 6 3. such that the flow will not erode the receiving downstream reach. Pipe outlets at the top of cuts or on slopes steeper than 10 percent cannot be protected by rock aprons or riprap sections due to reconcentration of flows and high velocities encountered after the flow leaves the apron. it shall be classified as a Maximum Tailwater Condition. 2. Culvert outlets of all types.Use Figure 3. Pipe conduits from all sediment basins. and permanent ponds. Conditions Where Practice Applies This practice applies where discharge velocities and energies at the outlets of culverts. If the tailwater depth is greater than half the pipe diameter and the receiving stream will continue to confine the flow. The upstream end of the apron. Alignment The outlet protection apron shall be straight throughout its entire length. or conform to pipe end section if used. There shall be no overfall at the end of the apron. (NOTE: Use of recycled concrete requires prior approval. the apron shall extend across the channel bottom and up the channel banks to an elevation one foot above the maximum tailwater depth or to the top of the bank. The elevation of the downstream end of the apron shall be equal to the elevation of the receiving channel or adjacent ground. Recycled concrete may be used provided it has a density of at least 150 pounds per cubic foot. does not have any exposed steel or reinforcing bars. by weight.2 .5. and 1. Materials The outlet protection may be done using rock riprap or gabions. whichever is less. adjacent to the pipe shall have a width two (2) times the diameter of the outlet pipe. The stone shall be hard.2 times the maximum stone size for d50 greater than 15 inches.10 . Bottom Grade The outlet protection apron shall be constructed with no slope along its length.5 times the d50 size. and is the proper size.3.5 times the maximum stone diameter for d50 of 15 inches or less.If the pipe discharges directly into a well-defined channel. Riprap shall be composed of a well graded mixture of stone size so that 50 percent of the pieces. The diameter of the largest stone size in such a mixture shall be 1. The specific gravity of the individual stones shall be at least 2.) 6 12/03 3. A well graded mixture is defined as a mixture composed primarily of larger stone sizes but with a sufficient mixture of other sizes to fill the smaller voids between the stones. angular and highly resistent to weathering. shall be larger than the d50 size determined by using the charts. The following chart lists some examples: ROCK RIPRAP SIZES AND THICKNESS d50 (inches) dmax (inches) NSA No. Min Blanket Thickness (inches) 6 9 12 24 9 14 18 36 R-4 R-5 R-6 R-8 14 20 27 43 Stone quality Stone for riprap shall consist of field stone or quarry stone. Thickness The minimum thickness of the riprap layer shall be 1. The area on which the gabion is to be installed shall be graded as shown on the drawings. Gabions shall be fabricated in such a manner that the sides. Where required. The maximum linear dimension of the mesh opening shall not exceed 4 1/2 inches and the area of the mesh opening shall not exceed 10-square inches.10 .3. ends.3 12/03 . Maintenance Once a riprap outlet has been installed.Filter A filter is a layer of material placed between the riprap and the underlying soil surface to prevent soil movement into and through the riprap. Gabions shall be of single unit construction and shall be installed according to manufacturers recommendations. The fabric shall meet the minimum performance criteria as specified in Appendix A-3. a key may be needed to prevent undermining of the main gabion structure. Foundation conditions shall be the same as for placing rock riprap and filter cloth shall be placed under all gabions. Gabions Gabions shall be made of hexagonal triple twist mesh with heavily galvanized steel wire. Riprap shall have a filter placed under it in all cases. 6 3. and lid can be assembled at the construction site into a rectangular basket of the specified size. It should be inspected after high flows to see if scour beneath the riprap has occurred. the maintenance needs are very low. or any stones have been dislodged. Repairs should be made immediately. The filter shall be a layer of Type GS-I geotextile material. 10 .3. Determine the tailwater condition at the outlet to establish which curve to use. Enter the appropriate chart with the depth of flow and discharge velocity to determined the riprap size and apron length required. the parameters of depth of flow and velocity must be used.5 + 38 = 43. = 66". Calculate apron width at the downstream end if a flared section is to be used. above pipe invert. diam. Example : Pipe Flow (full) with discharge to unconfined section A circular conduit is flowing full: Q = 280 cfs.2'. tailwater (surface) is 2 ft.4 . 2. 4. 3. Investigate the downstream channel to assure the non-erosive velocities can be maintained. For other than full pipe flow.5' 6 12/03 3. It is noted that references to pipe diameters in the charts are based on full flow. and apron length 38' Apron width = diam. + La = 5.Design Procedure 1. (minimum tailwater condition) Read d50 = 1. min.) NOTE: Curves should not be extrapolated.5 12/03 .10a Design of outtlet protection from a round pipe flowing full. minimum tailwater condition Source: USDA-NRCS 6 3. d50 = 6" Figure 3.10 .5 Dia.3.(Tw < 0.3. d50 = 6" Figure 3.5 Dia.) NOTE: Curves should not be extrapolated.10b Design of outtlet protection from a round pipe flowing full.10 .3. min. maximum tailwater condition Source: USDA-NRCS 6 12/03 3.3.(Tw > 0.6 . for ESC Section A-A TW < 0. ROP-1 DE-ESC-3.Standard Detail & Specifications Riprap Outlet Protection .3.1 A A DO W NOTE: Depress centerline of apron slightly to prevent edge-cutting Plan L a 0% T 1' Type GS-I geotextile fabric 1' NOTE: Key into exist.1 Sheet 1 of 2 6/05 Date: _________________ .10.5 DO Symbol: Detail No. & Specs. gnd DA DATTA Pipe diameter (DO) Apron length (La) Apron width (W) Riprap size (R No.) Riprap thickness (T) Source: Adapted from MD Stds. replace the entire filter cloth.1 Construction Notes: 1. ROP-1 DE-ESC-3.1 Sheet 2 of 2 6/05 Date: _________________ . Hand placement will be required to the extent necessary to prevent damage to the conduits.Standard Detail & Specifications Riprap Outlet Protection . cutting or tearing. 4. The riprap shall conform to the grading limits as shown on the plan. etc. All connecting joints should overlap a minimum of 1 ft. & Specs.3. structures. Any damage other than an occasional small hole shall be repaired by placing another piece of cloth over the damaged area. Filter cloth shall be protected from punching. for ESC Symbol: Detail No. Source: Adapted from MD Stds. Any fill required in the subgrade shall be compacted to a density of approximately that of the surrounding undisturbed material. The subgrade for the riprap shall be prepared to the required lines and grades as shown on the plan.10. 2. Riprap shall be placed in a manner to prevent damage to the filter cloth. 3. Stone for the riprap or gabion outlets may be placed by equipment. If the damage is extensive. 2 B A A W DO R = B DO Plan La 0% T 1' Type GS-I geotextile fabric 1' NOTE: Key into exist.Standard Detail & Specifications Riprap Outlet Protection .2 Sheet 1 of 2 12/03 Date: _________________ . Section B-B Source: Adapted from MD E&S Manual Symbol: Detail No.3.10.5 DO b d 6" Type GS-I geotextile fabric NOTE: Width of bottom (b) to vary from pipe diameter or end section width to existing channel bottom at end of riprap apron. ROP-2 DE-ESC-3. gnd Section A-A 4" W TW > 0. Filter cloth shall be protected from punching.2 DA DATTA Pipe diameter (DO) Apron length (La) Apron width (W) Bottom width (b) Riprap depth (d) Riprap size (R No. If the damage is extensive.Standard Detail & Specifications Riprap Outlet Protection . Any fill required in the subgrade shall be compacted to a density of approximately that of the surrounding undisturbed material. The subgrade for the riprap shall be prepared to the required lines and grades as shown on the plan. 3. 2. The riprap shall conform to the grading limits as shown on the plan. Riprap shall be placed in a manner to prevent damage to the filter cloth. cutting or tearing. Source: Adapted from MD E&S Manual Symbol: Detail No. Hand placement will be required to the extent necessary to prevent damage to the conduits. ROP-2 DE-ESC-3. All connecting joints should overlap a minimum of 1 ft. Stone for the riprap or gabion outlets may be placed by equipment. structures.3.) Riprap thickness (T) Construction Notes: 1.2 Sheet 2 of 2 12/03 Date: _________________ . Any damage other than an occasional small hole shall be repaired by placing another piece of cloth over the damaged area. replace the entire filter cloth. 4.10. etc. This applies to: 1. Culvert outlets of all types. Stone quality Stone for riprap shall consist of field stone or quarry stone. Conditions Where Practice Applies This practice applies where discharge velocities and energies at the outlets of culverts and conduits are sufficient to erode the downstream reach unless some type of energy dissipation structure is installed. The stone shall be hard. Design Criteria The design of riprap stilling basins shall be based on the maximum design discharge for the pipe or conduit. 2. Riprap shall have a filter placed under it in all cases. and permanent ponds.11 . 3. Pipe conduits from all sediment basins. 4. dry storm water ponds. Purpose: To reduce the velocity and energy of water.3. Recommended procedures for determining the configuration of the basin and sizing of the riprap are included in Design Guide 2. Recycled concrete may be used provided it has a density of at least 150 pounds per cubic foot. A design worksheet is also included. 6 3.) Filter A filter is a layer of material placed between the riprap and the underlying soil surface to prevent soil movement into and through the riprap. This is accomplished by inducing an hydraulic jump in the stilling basin prior to its discharge to a receiving channel or other stable outlet. angular and highly resistent to weathering. Situations where there is no defined outlet channel for the culvert or conduit.1 12/03 .STANDARD AND SPECIFICATIONS FOR RIPRAP STILLING BASIN Definition: A rock-lined plunge pool placed at the outlet end of culverts and conduits. and is the proper size. (NOTE: Use of recycled concrete requires prior approval. Situations which require a specific design velocity into a receiving channel. does not have any exposed steel or reinforcing bars. The specific gravity of the individual stones shall be at least 2. such that the flow will not create a scour hole at the point of discharge.5. The filter shall be a layer of Type GS-I geotextile material. The fabric shall meet the minimum performance criteria as specified in Appendix A-3. Repairs should be made immediately.2 .Maintenance Once a riprap stilling basin has been installed. It should be inspected after high flows to see if scour beneath the riprap has occurred. 6 12/03 3.3.11 . or any stones have been dislodged. the maintenance needs are very low. RSB DE-ESC-3.Standard Detail & Specifications Riprap Stilling Basin Half .3.11 Sheet 1 of 3 12/03 Date: _________________ .Plan Profile thru cL B asin Basin Source: Symbol: Adapted from FHWA HEC-14 Detail No. RSB DE-ESC-3.3.Standard Detail & Specifications Riprap Stilling Basin Section A-A Section B-B Section C-C SectionD-D DATA Culvert dimension (wO) Depth of basin from culvert invert (hS) Riprap size (R No.) Source: Symbol: Adapted from FHWA HEC-14 Detail No.11 Sheet 2 of 3 12/03 Date: _________________ . replace the entire section. Riprap shall be placed in a manner to prevent damage to the geotextile fabric. Source: Symbol: Adapted from FHWA HEC-14 Detail No. RSB DE-ESC-3. 3. structures. Fabric shall be protected from punching. 4. etc. 2. If the damage is extensive.Standard Detail & Specifications Riprap Stilling Basin Construction Notes: 1. The riprap shall conform to the grading limits as shown on the plan. Geotextile shall be a Type GS-I. Stone for the riprap or gabion outlets may be placed by equipment. Any damage other than an occasional small hole shall be repaired by placing another piece of cloth over the damaged area. cutting or tearing.11 Sheet 3 of 3 12/03 Date: _________________ . The subgrade for the riprap shall be prepared to the required lines and grades as shown on the plan. All connecting joints should overlap a minimum of 1 ft.3. Any fill required in the subgrade shall be compacted to a density of approximately that of the surrounding undisturbed material. Hand placement will be required to the extent necessary to prevent damage to the conduits. 12/03 Date: _________________ . Source: Symbol: Detail No.Standard Detail & Specifications Riprap Stilling Basin This page left intentionally blank. Topsoiling can delay seeding or sodding operations. The soil material is so shallow that the rooting zone is not deep enough to support plants or furnish continuing supplies of moisture and plant nutrients.STANDARD AND SPECIFICATIONS FOR TOPSOILING Definition: Placement of topsoil over a prepared subsoil prior to establishment of vegetation. stockpiling. Most topsoil contains weed seeds. Conditions Where Practice Applies: This practice is recommended for sites with slopes 2:1 or flatter where: 1. the option of topsoiling should be compared with that of preparing a seedbed in subsoil. Stripping. there are disadvantages to its use. carrying much of the nutrients available to plants. High-quality turf and/or landscape plantings are to be established. Purpose: To provide a suitable growth medium for final stabilization with vegetation. and reapplying topsoil or importing topsoil. Although topsoil provides an excellent growth medium. subsoils may provide a good growth medium which is generally free of weed seeds. 5. may not always be cost-effective. and supplying a large share of the water used by plants.1 12/03 . In many cases 6 3. The texture of the exposed subsoil or parent material is not suitable to produce adequate vegetative growth. The clay content of subsoils does provide high moisture availability and deter leaching of nutrients and. In site planning. Planning Considerations: Topsoil is the surface layer of the soil profile. and nutrient content.4. and weeds may compete with desirable species. It is the major zone of root development. The original soil to be vegetated contains material toxic to plant growth. 2. increasing the exposure time of denuded areas. The soil is so acid that treatment with limestone is not feasible. 4. generally characterized as being darker than the subsoil due to the presence of organic matter. 3. Advantages of topsoil include its high organic matter content and friable consistence. when properly limed and fertilized.1 . water-holding capacity. 4.1 . The following considerations should be given to any topsoiling operation: 1.2 . soils containing potentially toxic materials. Ensure an adequate volume of topsoil exists on the site. 2. as water may seep along the interface between the soil layers. and mulch the topsoiled area. compact. (See Section 3. This will require additonal volume than if it were merely spread loosely. Topsoiling is strongly recommended where ornamental plants or high-maitenance turf will be grown. Stockpiles should be located so as not to interfere with other site work. seed. 6. In order to improve this bonding. treat.) 6 12/03 3. Clayey topsoil over sandy subsoil is a particularly poor combination.2. Topsoiling of steep slopes should generally be avoided unless adequate measures have been taken to prevent slope failure. lower maintenance plant material. 4. 5. and soils of critically low pH (high acid) levels.4.topsoiling may not be required for the establishment of less demanding. Topsoiling is a required procedure when establishing vegetation on shallow soils. causing the topsoil to slough. the subsoil should be scarified prior to spreading of the topsoil. Topsoil should be compacted to a preferred depth of 4 inches. Standard & Specification for Slope Treatment. Sandy topsoil over a clay subsoil may aslo be prone to failure. Care must be taken not to apply topsoil to a subsoil having major textural differences. 3. If topsoil and subsoil are not properly bonded. making it difficult to establish vegetation. water will not infiltrate the soil profile evenly. Project scheduling must account for the time to spread. b. 2. Liming . c. Pack by passing a bulldozer up and down over the entire surface area of the slope to create horizontal erosion check slots to prevent topsoil from sliding down the slope. grade stabilization structures.After the areas to be topsoiled have been brought to grade. Site Preparation (Where Topsoil is to be added) Note: When topsoiling. berms.1 USDA . a. Tilling . and immediately prior to dumping and spreading the topsoil.4.Standard Detail & Specifications Topsoiling Construction Notes: 1.000 square feet). Source: Symbol: Detail No.Grades on the areas to be topsoiled which have been previously established shall be maintained. dikes. the subgrade shall be loosened by discing or by scarifying to a depth of a least 3 inches to permit bonding of the topsoil to the subsoil. maintain needed erosion and sediment control practices such as diversions. Grading . Lime shall be distributed uniformly over designated areas and worked into the soil in conjunction with tillage operations as described in the following procedures.Where the topsoil is either highly acid or composed of heavy clays. waterways and sediment basins.NRCS Sheet 1 of 2 12/03 Date: _________________ . ground limestone shall be spread at the rate of 4-8 tons/acre (200-400 pounds per 1. Topsoil Material and Application Note:Topsoil salvaged from the existing site may often be used but it should meet the same standards as set forth in these specifications. DE-ESC-3. The depth of topsoil to be salvaged shall be no more than the depth described as a representative profile for that particular soil type as described in the soil survey published by USDA-SCS in cooperation with Delaware Agricultural Experimental Station. All topsoil shall be tested by a reputable laboratory for organic matter content. pH and soluble salts. trash or other extraneous materials larger than 1-1/2 inches in diameter. or others as specified. stones. gravel. Note: No sod or seed shall be placed on soil which has been treated with soil sterilants or chemicals used for weed control until sufficient time has elapsed to permit dissipation of toxic materials. Grading . slag. Topsoil shall not be placed while in a frozen or muddy condition. thistles.5 and an organic content of not less than 1. clay loam. nutsedge. It shall not have a mixture of contrasting textured subsoil and contain no more than 5 percent by volume of cinders. A pH of 6. roots.Standard Detail & Specifications Topsoiling Construction Notes (cont. quackgrass. Any irregularities in the surface resulting from topsoiling or other operations shall be corrected in order to prevent the formation of depressions or water pockets. DE-ESC-3. Spreading shall be performed in such a manner that sodding or seeding can proceed with a minimum of additional soil preparation and tillage.5 percent by weight is required. Johnsongrass. sticks.NRCS Sheet 2 of 2 12/03 Date: _________________ . Source: Symbol: Detail No. may be used in lieu of natural topsoil. Topsoil must be free of plants or plant parts of bermudagrass. coarse fragment. sandy loam.4. or in a condition that may otherwise be detrimental to proper grading and seedbed preparation. Note:Topsoil substitutes or amendments as approved by a qualified agronomist or soil scientist.The topsoil shall be uniformly distributed and compacted to a minimum of four (4) inches.1 USDA .5 or higher. when the subgrade is excessively wet. silt loam. Materials .0 to 7. sandy clay loam.) a. Topsoil containing soluble salts greater than 500 parts per million shall not be used.Topsoil shall be a loam. poison ivy. loamy sand or other soil as approved by an agronomist or soil scientist. If pH value is less than 6.0 lime shall be applied and incorporated with the topsoil to adjust the pH to 6. b. 4:1 is preferred because of safety factors related to mowing steep slopes. Design Criteria The grading plan should be based on incorporating buildings.) 6 3. The flow length within a bench shall not exceed 800' unless accompanied by an appropriate design and computations. The plan shall also include phasing of these practices. unless accompanied by appropriate design and computations.2 . with the existing topography and landscape whenever possible in order to avoid major grade modifications.) Slopes steeper than 2:1 shall require special design and stabilization considerations that shall be adequately shown on the plans. (Where the slope is to be mowed the slope should be no steeper than 3:1..4. 30 feet for a 3:1 slope. The following shall be incorporated into the plan: 1. Benches shall be provided whenever the vertical interval (height) exceeds 20 feet for a 2:1 slope. Standard and Specifications for Diversion. Provisions shall be made to safely conduct surface runoff to storm drains. or to stable water courses to insure that surface runoff will not damage slopes or other graded areas. The plan must show existing and proposed contours of the area(s) to be graded. protected outlets. etc. 3. seeps. utilities. streets. or 40 feet for a 4:1 slope. The plan shall also include approved practices for erosion control. a. 2. rock outcrops. b. Soils. Benches shall be located to divide the slope face as equally as possible and shall convey the water to a stable outlet.3. slope stabilization. Purpose: To provide for erosion control and vegetative establishment on those areas which are more prone to erosion due to topography. Cut slopes that are to be stabilized with grasses shall not be steeper than 2:1. (See Section 3. etc. The gradient to the outlet shall be between 2 percent and 3 percent. Benches shall be designed with a reverse slope of 6:1 or flatter to the toe of the upper slope and with a minimum of one foot in depth. safe disposal of runoff water and drainage.5. c. The information submitted must provide sufficient topographic surveys and soil investigations to determine limitations that must be imposed on the grading operation.1 6/05 .STANDARD AND SPECIFICATIONS FOR SLOPE TREATMENT Definition: Grading of sloped areas of a site in a way so as to minimize potential erosive forces. shall also be taken into consideration when designing diversions. Benches shall be a minimum of six-feet wide to provide for ease of maintenance. Fill slopes that are to be stabilized with grasses shall not be steeper than 3:1. etc. Stockpiles. Cut slopes occurring in ripable rock shall be serrated as shown on the appropriate detail. and other objectionable material. 10. b. Subsurface drainage shall be provided where necessary to intercept seepage that would otherwise adversely affect slope stability or create excessively wet site conditions. except where: a. Each step or serration shall be constructed on the contour and will have steps cut at nominal two-foot intervals with nominal three-foot horizontal shelves. 6. These steps will vary depending on the slope ratio or the cut slope.4. subsidence or other related damages. The face of the slope will be protected by special erosion control materials. These serrations shall be made with conventional equipment as the excavation is made. rubbish. These steps will weather and act to hold moisture. 9. Slopes shall not be created so close to property lines as to endanger adjoining properties without adequately protecting such properties against sedimentation. fertilizer and seed thus producing a much quicker and longer lived vegetative cover and better slope stabilization. gravel. rocks.4. 8. The face of the slope shall not be subject to any concentrated flows of surface water such as from natural drainageways. All disturbed areas shall be stabilized in accordance with the Standards and Specifications for Mulching and Vegetative Stabilization. downspouts. sod. The nominal slope line is 1 1/2 : 1.2 . 6 6/05 3. stumps. erosion. 7. 5. riprap or other stabilization method. lime. borrow areas. slippage. settlement. ditches and swales or conveyed downslope by the use of a designed structure. The face of the slope is or shall be stabilized and the face of all graded slopes shall be protected from surface runoff until they are stabilized. and spoil areas shall be shown on the plans and shall be subject to the provision of this Standard and Specifications. Surface water shall be diverted from the face of all cut-and-fill slopes by the use of diversions. Overland flow shall be diverted from the top of all serrated cut slopes and carried to a suitable outlet.2 . It should be free of stones over two (2) inches in diameter where compacted by hand or mechanical tampers or over eight (8) inches in diameter where compacted by rollers or other equipment. graded swales. building debris. c. logs. Frozen material shall not be placed in the fill nor shall the fill material be placed on a frozen foundation. Fill material shall be free of brush. ST-B DE-ESC-3. for ESC Symbol: Detail No. Y 2:1 or f latt er X 6' min.1 Sheet 1 of 2 12/03 Date: _________________ .Benching Diversion or temporary dike to divert flow (if required) Bench to have 2-3% grade and drain to stable outlet H (1' min).) 2 3 4 20' 30' 40' Perspectiv erspectivee DATA Slope (X:1) Vertical height (Y) Bench height (H) Source: Adapted from MD Stds.2.4. Slope X:1 Y (max. & Specs.Standard Detail & Specifications Slope Treatment . All diversions shall be kept free of sediment during all phases of development. ST-B DE-ESC-3.2. mucky or highly compressible materials shall not be incorporated into fills. fill material shall be free of brush. All graded areas shall be permanently stabilized immediately following finished grading. Areas which are to be topsoiled shall be scarified to a minimum depth of three (3) inches prior to placement of topsoil.Benching Construction Notes: 1.4. logs. 4. for ESC Symbol: Detail No. slippage. rubbish. Seeps or springs encountered during construction shall be handled in accordance with the Standard and Specifications for Subsurface Drain or other approved methods. All fill is to be placed and compacted in layers not to exceed 8 inches in thickness. 5.Standard Detail & Specifications Slope Treatment . Stockpiles. 7. Except for approved landfills. grubbed and stripped of topsoil to remove trees. roots or other objectionable material. 8 Frozen materials or soft. borrow areas and spoil areas shall be shown on the plans and shall be subject to the provisions of this Standard and Specifications. 3. Topsoil required for the establishment of vegetation shall be stockpiled in amounts necessary to complete finished grading of all exposed areas. rocks. 10. settlement. 6. 9. 11. Fill material shall not be placed on a frozen foundation. stumps. & Specs. Source: Adapted from MD Stds. 13. 12. Areas to be filled shall be cleared. vegetation. All graded or disturbed areas including slopes shall be protected during clearing and construction in accordance with the approved sediment control plan until they are permanently stabilized. building debris and other objectionable materials that would interfere with or prevent construction of satisfactory fills. 2.1 Sheet 2of 2 12/03 Date: _________________ . subsidence or other related problems. All fills shall be compacted as required to reduce erosion. 3" (ty p.4. ST-G DE-ESC-3. soil and amendments are trapped by grooves during minor erosion events.Grooving 12" -15 " (t yp.Standard Detail & Specifications Slope Treatment . ) Seed.2. Section Source: Adapted from VA ESC Handbook Symbol: Detail No.2 Sheet 1 of 2 12/03 Date: _________________ .) NOTE: Grooving can be established by raking across the slope with appropriate equipment or by running tracked equipment up and down the slope. Seeps or springs encountered during construction shall be handled in accordance with the Standard and Specifications for Subsurface Drain or other approved methods. Topsoil required for the establishment of vegetation shall be stockpiled in amounts necessary to complete finished grading of all exposed areas. 3. vegetation. grubbed and stripped of topsoil to remove trees. slippage. Source: Adapted from VA ESC Handbook Symbol: Detail No. 5. Except for approved landfills.2. roots or other objectionable material. Areas to be filled shall be cleared. Areas which are to be topsoiled shall be scarified to a minimum depth of three (3) inches prior to placement of topsoil. 12. All graded or disturbed areas including slopes shall be protected during clearing and construction in accordance with the approved sediment control plan until they are permanently stabilized. 6.2 Sheet 2 of 2 12/03 Date: _________________ . 11. Fill material shall not be placed on a frozen foundation. rocks. logs. building debris and other objectionable materials that would interfere with or prevent construction of satisfactory fills. 10. fill material shall be free of brush. 8 Frozen materials or soft. 7.Standard Detail & Specifications Slope Treatment . All diversions shall be kept free of sediment during all phases of development. All fills shall be compacted as required to reduce erosion. 13. All graded areas shall be permanently stabilized immediately following finished grading. borrow areas and spoil areas shall be shown on the plans and shall be subject to the provisions of this Standard and Specifications. subsidence or other related problems. stumps.Grooving Construction Notes: 1. All fill is to be placed and compacted in layers not to exceed 8 inches in thickness. 4. ST-G DE-ESC-3. settlement. mucky or highly compressible materials shall not be incorporated into fills. Stockpiles. rubbish. 2.4. 9. Standard Detail & Specifications Slope Treatment . ST-S DE-ESC-3..) Diversion or temporary berm to divert surface flow from slope (if required) Neg.Serrating Debris may be left on shelves to aid establisment of vegetation 3' (typ.3 Sheet 1 of 2 12/03 Date: _________________ .) 4:1 Section NOTE: Serr ating is applicable to rippable rock slopes only Serrating only.) Nominal slope line of 1.5:1 (typ.2. Source: Adapted from VA ESC Handbook Symbol: Detail No. slope 2' (typ.4. Stockpiles.2. building debris and other objectionable materials that would interfere with or prevent construction of satisfactory fills. 4. slippage. settlement.4. All fill is to be placed and compacted in layers not to exceed 8 inches in thickness. 6. 10. Frozen materials or soft. fill material shall be free of brush. stumps. Fill material shall not be placed on a frozen foundation. 8. Topsoil required for the establishment of vegetation shall be stockpiled in amounts necessary to complete finished grading of all exposed areas. 2. 7. rubbish.3 Sheet 2 of 2 12/03 Date: _________________ . 3. mucky or highly compressible materials shall not be incorporated into fills. All diversions shall be kept free of sediment during all phases of development. logs. rocks. 9. ST-S DE-ESC-3. Seeps or springs encountered during construction shall be handled in accordance with the Standard and Specifications for Subsurface Drain or other approved methods.Standard Detail & Specifications Slope Treatment . All graded areas shall be permanently stabilized immediately following finished grading. Except for approved landfills. subsidence or other related problems. Source: Adapted from VA ESC Handbook Symbol: Detail No. All graded or disturbed areas including slopes shall be protected during clearing and construction in accordance with the approved sediment control plan until they are permanently stabilized. borrow areas and spoil areas shall be shown on the plans and shall be subject to the provisions of this Standard and Specifications. 11.Serrating Construction Notes: 1. All fills shall be compacted as required to reduce erosion. 5. It is less costly to carry on a maintenance program than it is to make repairs after an extended period of neglect. The vegetation shields the soil surface from the impact of falling raindrops. Purpose: Preserving or establishing a cover of healthy vegetation is the most effective and economical means for preventing soil erosion. Soil ammendments. 55). to preserve as much of the existing vegetation as possible by limiting grading. On large sites. it can minimize the erosion potential of a construction site and reduce the need for structural practices. improves and maintains the infiltrative capacity of the soil. If graded areas are to remain idle for extended periods of time. holds soil particles in place. and removes subsurface water through evapotranspiration. grade and stabilize in stages.1 12/03 . a grass cover placed on bare ground will reduce runoff from a one (1) year frequency storm event (2. slows runoff. It is important. depending on the soil type (Calculation based on Soil Conservation Service Technical Release No. The cost savings from reduced maintenance may be much greater than the cost of temporary seeding. 6 3. The success of vegetative establishment depends on proper application.STANDARD AND SPECIFICATIONS FOR VEGETATIVE STABILIZATION Definition: The preservation and/or establishment of vegetation to prevent the erosion of disturbed areas. tree pruning and removal of invasive or undesirable plants. weed management. The steps for proper stabilization are: 6 6 6 6 Site preparation. This may significantly reduce the amount of maintenance required for structural controls at the construction site.4.3 .8 inches of rainfall) by 50-100 percent. Maintenance typically includes mowing. Seed application and Mulching and mulch anchoring. so that one area is re-vegetated before another is cleared. Because vegetation is so effective in reducing runoff. pest and disease control. For example. Stands of vegetation also need to be maintained to assure their continuing vigor and function. the establishment of a temporary vegetative cover will reduce the runoff and erosion potential. installation and care. fertilizer and lime application. therefore. Details for each of these steps must be included on all sediment and stormwater plans. 4. 6 12/03 3. structure. In summary.2 . shrubs.3 . or the local Conservation District. Maintaining vegetation will ensure that these benefits will continue for the long term. windbreaks and aesthetic enhancements. For unusual or site specific applications. This provides better environmental protection and may reduce construction costs by limiting the number of structural practices required and associated maintenance costs. The following sections contain additional standards and specifications for both temporary and permanent vegetative stabilization. including sodding.Planting vegetation such as trees. There are also several tables and charts to assist the designer in selecting the appropriate plant material for a given set of conditions. These plants are usually reserved for special purpose. the local field office of the Natural Resources Conservation Service. preserving the existing vegetation or establishing a new temporary or permanent vegetative cover as soon as possible after grading reduces runoff and erosion. vines and ground covers on disturbed areas offers an alternative to grasses and provides additional functions such as wildlife food and cover. high value landscaping. Additional information may be obtained through the local office of the Delaware Cooperative Extension System. the Delaware Forest Service. slope or water movement. it would be best to engage a landscape architect or consulting forester. This practice cannot be expected to provide an erosion control cover and prevent soil slippage on a soil that is not stable due to its texture. This information is beneficial both economically and environmentally. 4. The sample should reflect the site conditions that are to be stabilized with vegetation. Zn. 2. timely. Cu. Mg. lime requirement. the topsoil. 3. compaction. auger or spade. Determining the fertility of the soil will provide the precise amount of nutrients needed to establish lawns or other plantings. soil sample bags. K. establishing vegetation can prove to be unsuccessful.3 12/03 . P. Soil testing materials including a sampling tube. Planning Considerations: During site construction the top layer of the soil. The topsoil is an important layer in the soil where plants establish their roots and extract the necessary nutrients for growth and survival. The soil sample along with a small fee is then forwarded to the University of Delaware where the testing occurs. The soil to be vegetated contains material toxic to plant growth. pH. Purpose: Soil testing will serve the following purposes: 1. Soil tests provide the fertility of the soil and whether lime or additional fertilizer may be required for successful plant growth. High-quality turf and/or landscape plantings are to be established. 6 3. 2. and overall costly. and sampling instructions available at your County Cooperative Extension office. To provide suitable growth medium for final stabilization with vegetation. A soil sample weighing approximately ½ pound is used to represent thousands of pounds of soil on the subject parcel of land. Existing soil conditions are not suitable to produce adequate vegetation growth. Large areas are to be planted with the same type of vegetation (to minimize entire areas with unsuccessful germination or plant survival due to poor soil conditions).3 . Conditions Where Practice Applies: Soil testing is recommended for all sites that will be stabilized with vegetation where: 1. is altered through grading. Obtaining the Soil Sample: An accurate soil test can only be achieved through obtaining a good soil sample. buffer pH. Significant amounts of topsoil have been removed from the site through excavation or grading. When the topsoil is stripped from the site. To apply the appropriate amount of lime or fertilizer for optimal plant growth. Additional information can be requested. Ca. Mn. Soil tests provide the following information. The soil samples must be placed in the designated cloth bags that are provided at the Extension office. and organic matter by LOI.ADDITIONAL STANDARD AND SPECIFICATIONS FOR SOIL TESTING Definition: Soil is tested to determine the fertility status so that the required amount of lime and fertilizer is applied for optimal plant growth. sample information sheets. and excavation. 5.4. 3 .1. Remove any leaf litter or debris before sampling. Additional Information Contact the local Cooperative Extension Office for methods of applying lime and fertilizers. Do not take samples in areas that are significantly different. Stay away from lanes or border areas. 5. Fill the sample bag to the level indicated and discard the rest of the material. 1. Steel sampling tools and plastic buckets are recommended for obtaining the sample. 2. lawns need only be sampled every 2 to 3 years. with annual reports submitted by March 1 of the calendar year. A Nutrient Management Plan is a strategy to manage the amount. How often should soil be tested? 1. Where liming is likely. DE 19716-1303 (302)-831-2506. timing and application of nutrients. 2004. Do Not Contaminate the Sample 1. 2. 4. fertilizer.D. 2. 3. or lime on tools or hands can contaminate a soil sample.4 . R. 6 12/03 3. sandy ridges and eroded areas should be avoided. all persons who control the application of nutrients to 10 acres or greater shall develop and implement a Nutrient Management Plan and become certified by the program. Newark. Sussex County: University of Delaware. Because lime reacts slowly. (302) 856-7303. Do not use sample bags other than those provided by the laboratory. it should be mixed with soil several months before planting. Spread the mixture out on clean paper to dry. Chemicals. The maximum sample area for one soil test is 40 acres. Georgetown. Your recommendations will be no better than the information submitted. Each core should be taken to a depth of 6 to 9 inches. Locate sample locations on a map or sketch. Use clean tools to obtain the sample. DE 19947. Name each sample and keep a complete record of the area represented. 3. placement. (302) 697-4000. The Plan shall be updated every three years. 2. Box 48. DE 19901. Place cores in a clean plastic pail and mix them together thoroughly. Research and Education Center. 6. Anomalies such as potholes. 4. The soil sample should consist of 15 to 25 cores taken from the sampling area. 6. Kent County: 2319 South DuPont Highway.4. New Castle County: 910 South Chapel Street. 2. Vegetable gardens should be sampled every 1 to 2 years. 3. sample well in advance of planting. 3. Once adequate fertility levels are established. Completely fill out the information sheet provided with each sample bag and place in the attached envelope. 7. Areas where soil and vegetation conditions appear different should be sampled separately. Dover. Forwarding the Sample 1. NOTE: Effective January 1. 4. Seedbed Preparation It is important to prepare a good seedbed to insure the success of establishing vegetation. However. loose.Apply fertilizer based on the recommendations of a soil test in accordance with the approved nutrient management plan. Apply fertilizer uniformly and incorporate into the top 4 to 6 inches of soils. 2. If a nutrient management plan is not required.Soil amendments are not typically required for temporary stabilization.3. uniform. and sediment basins. 3. Specifications 1. Final grading and shaping is not necessary for temporary seedings.5 12/03 . Prior to seeding.3. The soil surface should not be compacted or crusted. b.3 . and to provide protection to disturbed areas until permanent vegetation or other erosion control measures can be established. b. Additional Standards and Specifications for Soil Testing. apply dolomitic limestone at the rate of 1 to 2 tons per acre.ADDITIONAL STANDARD AND SPECIFICATIONS FOR TEMPORARY STABILIZATION Definition: The planting of quick growing vegetation to provide temporary stabilization on disturbed areas. For additional information. berms. Fertilizer .4. reduce damage from sediment and runoff to downstream or off-site areas. If a nutrient management plan is not required. Lime . in some cases soil conditions may be so poor that amendments are needed to establish even a temporary vegetative cover. apply a formulation of 10-1010 at the rate of 600 pounds per acre. Under these extreme conditions.Apply liming materials based on the recommendations of a soil test in accordance with the approved nutrient management plan. grassed waterways. grade stabilization structures.1. For additional information. The seedbed should be well prepared. and free of large clods. Soil Amendments . Additional Standards and Specifications for Soil Testing.4.1. rocks. the following guidelines should be used: a. Site Preparation a. and other objectionable material. install needed erosion and sediment control practices such as diversions. 6 3. see Section 3. Conditions Where Practice Applies Graded or cleared areas which are subject to erosion for a period of 14 days or more. Purpose: To temporarily stabilize the soil. dikes. see Section 3. Apply limestone uniformly and incorporate into the top 4 to 6 inches of soil. 6 . Seed that has been broadcast should be covered by raking or dragging and then lightly tamped into place using a roller or cultipacker. b. cultipacker seeder or hydroseeder. All seed will be applied at the recommended rate and planting depth.4.3. 6 12/03 3. c. Seeding a.3 . Standard and Specifications for Mulching.4. Select a mixture from Figure 3. drill.4. If hydroseeding is used and the seed and fertilizer is mixed. 5.2a.4. Mulching All mulching shall be done in accordance with Section 3. Apply seed uniformly with a broadcast seeder.5. they will be mixed on site and the seeding shall be done immediately and without interruption. 5 inches 1-2" sandy soils 0.5 inches 1-2" sandy soils 1. Seed at 3-5 lbs.3. Good on low fertility and acid areas. May be planted throughout summer if soil moisture is adequate or seeded area can be irrigated.7 12/03 . 2.4. Fifty pounds per acre of Annual Lespedeza may be added to 1/2 the seeding rate of any of the above species.ft. 3.5 O O A 1-2 inches 2-3" sandy soils 1-2 inches 2-3" sandy soils 1-2 inches 2-3" sandy soils 0.2a Temporary seeding guidelines 6 3.7 O O 8 Pearl Millet 20 PLS 0. Winter seeding requires 3 tons per acre of straw mulch for proper stabilization.5 inches 1-2" sandy soils 1-2 inches 2-3" sandy soils 0.5". Warm season grasses such as Millet or Weeping Lovegrass may be used between 5/1 and 9/1 if desired.5 inches 1-2" sandy soils 0. 4. Figure 3.5 lb/1000 sq. Seed after frost through summer at a depth of 0.TEMPORARY SEEDING BY RATES.3 . A = Acceptable Planting Period All 5/17/31 8/110/31 10/312/1 1 Barley 125 4 O A O O A O 2 Oats 125 4 O A A O A A 3 Rye 125 4 O A O O A O 4 Perennial Ryegrass 125 4 O A O O A O 5 Annual Ryegrass 125 4 O A O O A O A 6 Winter Wheat 125 4 O A O O A O A 7 Foxtail Millet 30 PLS 0. Contact a County Extension Office for information. Applicable on slopes 3:1 or less. Use varieties currently recommended for Delaware.4. 2/14/30 2 5/18/14 Piedmont 8/153/1-4/30 10/31 2 Planting Depth 3 O = Optimum Planting Period. DEPTHS AND DATES Seeding Rate Species6 Mix # Optimum Seeding Dates 1 Coastal Plain Certified Seed lb/Ac . per acre. 5. 6. 6 12/03 3.4.This page left intentionally blank.8 .3 . However. 6 3. All irregularities in the surface must be corrected in order to prevent the formation of depressions or water pockets. dikes. Sufficient pore space to permit adequate root penetration. and other objectionable material. Grade as needed and feasible to permit the use of conventional equipment for seedbed preparation. 2. berms. grade stabilization structures. The soil shall be free from any material harmful to plant growth. it cannot be expected to provide an erosion control cover and prevent soil slippage on a soil that is not stable due to its texture. install needed erosion and sediment control practices such asdiversions.9 12/03 .3 .4. Seedbed Preparation a. and free of large clods. b. which can be planted on a sandy soil. Purpose: To permanently stabilize soil on disturbed areas and to reduce sediment and runoff to downstream or off-site areas. vegetation is the preferred method of stabilizing bare soil because of its numerous benefits.1. Conditions Where Practice Applies Graded or cleared areas subject to erosion and where a permanent. b. and sediment basins. Site Preparation a.4. rocks. The seedbed shall be well pulverized. If these conditions cannot be met. In most cases. Specifications 1. uniform. 3. anchoring and maintenance. The top layer of soil shall be loosened by raking. seeding. disking or other acceptable means before seeding. Standard and Specifications for Topsoiling. Prior to seeding. It is important to prepare a good seedbed to insure the success of establishing vegetation. A noticeable exception would be planting lovegrass and serecia lespedeza. water movement or excessively steep slope. long-lived vegetative cover is needed. mulch application. Minimum Soil Conditions Needed for the Establishment and Maintenance of Permanent Vegetative Cover 1. loose. structure. Enough fine-grained materials to provide the capacity to hold at least a moderate amount of available moisture. see Section 3. Flat areas and slopes up to 3:1 grade shall be loose and friable to a depth of at least 4 inches. grassed waterways. 4. 2.ADDITIONAL STANDARD AND SPECIFICATIONS FOR PERMANENT STABILIZATION Definition: The establishment of perennial vegetation to provide permanent stabilization on disturbed areas. 4. All of the data on the tag relates in some way to the seed in the bag. should be agitated to prevent stratification in the box. 6 “Lot” refers to the specific lot of seed tested.4. Slopes steeper than 3:1 shall have the top 1-3 inches of soil loose and friable before seeding. This tag contains essential information about the content and quality of the turf seed therein.1. 6 “Inert Matter” is the percentage of dust.10 . When hydroseeding is the chosen method. Soil Amendments a.3a. see Section 3. Drill seeding is the preferred method. especially when light. the lime and fertilizer shall be worked in the best way possible. such as those found on drill seeders. Additional Standards and Specifications for Soil Testing. 6 “% Germination” refers to the percentage of seed that germinated during testing. Following is a list of items and information that they represent: 6 “Product” is the species or type of seed that was tested.On sloping land. 6 “% Purity” is the number of seeds of a species/variety. Seeding a. Some seeders are also equipped with multiple boxes to separate the seed by species. “VNS” means “Variety Not Stated” indicating uncertainty about the quality and characteristics of the seed. chaff. Lime . 3. of the total weight of the tested sample. If a nutrient management plan is not required. “Net Weight” and “Date Tested” are self-explanatory. drill.Apply fertilizer based on the recommendations of a soil test in accordance with the approved nutrient management plan. Fertilizer . On slopes steeper than 3:1.4. For additional information. stems.4. 6 12/03 3. Apply seed uniformly with a broadcast seeder. All seed will be applied at the recommended rate and planting depth. see Section 3. c. Seed mixtures loaded into boxes or containers. 6 “Weed Seed” refers to the percentage of weed seeds in a sample. found in the mix. Select a mixture from Figure 3. production field and components in the bag. the final disking and harrowing operation should be on the contour wherever feasible. the total rate of seed should be increased by 25% over the rates recommended in Figure 3.c. For additional information.3. 6 “Noxious Weeds” are the weed seeds considered by local law to be noxious. Every bag of seed is required by law to have an analysis tag attached to it. soil. apply 10-10-10 at the rate of 600 pounds per acre.3.3.Apply liming materials based on the recommendations of a soil test in accordance with the approved nutrient management plan. resulting in even distribution. Apply fertilizer uniformly and incorporate into the top 4 to 6 inches of soils. Incorporation . providing a tracking of the varieties. c.3. apply dolomitic limestone at the rate of 1 to 2 tons per acre. If a nutrient management plan is not required. Apply limestone uniformly and incorporate into the top 4 to 6 inches of soil. etc.3a. 4. fluffy seeds are in the mix. 6 “Other Crop Seeds” is the percentage of crop seeds of the tested sample that have been found during a physical separation of the sample. expressed as percentages of the whole. b. 6 “Origin”.4. Additional Standards and Specifications for Soil Testing.3 . b.1. cultipacker or hydroseeder. This number must always be zero. 3. Irrigation a. b. it may be necessary to irrigate.1. When any of these or other unusual site conditions are encountered. 8. or re-establish plantings in order to provide permanent vegetation for adequate erosion control. extremely low fertility soils. For additional information. seed species. Maintenance a. Lime according to soil test recommendations at least once every five years. alternative vegetative stabilization techniques are necessary. Depending on site conditions. Additional Standards and Specifications for Soil Testing. at least every two years. see Section 3. 7. 6.4. If hydroseeding is used and the seed and fertilizer is mixed. Mulching All mulching shall be done in accordance with Section 3. Fall seedings may require the same between March 15 and May 1 the following year. mixtures and rates other than those listed in the following tables in order to achieve successful stabilization. fertilize. acidic soils (pH less than 4. Spring seedings may require an application of fertilizer between September 1 and October 15. overseed.0) and dune stabilization. Inspect seeded areas for failure and reestablish vegetation as soon as possible.d. Examples include steeply sloped areas. they will be mixed on site and the seeding shall be done immediately and without interruption. Special Conditions Under certain site conditions. DNREC and/or the appropriate delegated agency may require products. If slow release fertilizer is used. Irrigation must be carefully controlled to prevent runoff and subsequent erosion. Daily irrigation can be critical in establishing permanent vegetation during dry or hot weather or on adverse site conditions. It takes one full year to establish permanent vegetation from the time of planting. Maintenance fertilization rates should be established by soil test recommendations in accordance with an approved nutrient management plan. Inadequate or excessive irrigation can do more harm than good. follow-up fertilizations may not be necessary for several years. 6 3. Standards and Specifications for Mulching.4.4.11 12/03 . 5. Seed that has been broadcast must be covered by raking or dragging and then lightly tamped into place using a roller or cultipacker.3 .5. Adequate moisture is essential for seed germination and plant growth. b. ft. Drought tolerant.05 5 3 3 2 0.46 0.11 1.23 0.weeds Managed filter strip for nutrient uptake.7 Switchgrass or Coastal Panicgrass Big Bluestem Little Bluestem Indian Grass Tall Fescue (turf-type) (Blend of 3 cultivars) Tall Fescue Ky.3 . O A O O A O Add 100 Suitable waterway mix. Creeping Red Rye Fescue for heavy shade.34 2.23 0.8/15.4.15 0.5/1.69 0.15 1.23 lb/1000 sq.07 0. Canada Bluegrass more Winter drought tolerant. All4 Coastal Plain Piedmont 2/1. Tolerant of low fertility soils.8/110/31-2/1 4/30 8/14 10/31 4/30 7/31 10/31 A O A A O A Add 100 Good erosion control mix lbs. Rye Use Redtop for increased drought tolerance./ac Tolerant of low fertility soils Winter Good wildlife cover and food Rye O A O O A O Add 100 Good erosion control mix lbs.46 0.69 0./ac Tolerant of low fertility soils Winter Lovegrass very difficult to mow. O = Optimum Planting Period A = Acceptable Planting Period Optimum Seeding Dates 2 PERMANENT SEEDING AND SEEDING DATES .69 0.5/1.4./ac. Three cultivars of Kentucky Bluegrass.35 0.3. All species are native.07 0.5 0. Tall Fescue for droughty Winter conditions./ac. lb/Ac Seeding Rate1 Tall Fescue Well Drained Soils Certified Seed3 Seeding Mixtures Remarks O O O A A A O O O O O O A A A O O O Creeping Red Fescue will provide erosion protection while the warm season grasses get established. 6.5 0. Traffic tolerant.3a Seed mixes and recommended seeding dates 6 12/03 3. Rye Germinates only in hot weather A O A A O A Add 100 Good erosion control mix lbs. Indian Grass and Bluestem have fluffy seeds. Bluegrass (Blend) Perennial Ryegrass 7 Big Bluestem 7 Indian Grass 7 Little Bluestem Creeping Red Fescue plus one of: Partridge Pea Bush Clover Wild Indigo Showy Tick-Trefoil plus White Clover5 plus Flatpea5 Strong Creeping Red Fescue Kentucky Bluegrass Perennial Ryegrass or Redtop 3.23 0. N fertilizer discouraged .12 8 7 6 5 4 3 2 1 Mix No.07 0.3/1. lbs.61 0.11 0. Flatpea to suppress woody vegetation.35 0. Poor shade tolerance.23 0.15 1.Figure 3.11 0.18 0.11 0. Plant with a specialized native seed drill. 3. Native warm-season mixture.1 3.2 150 20 20 10 10 8 30 3 10 10 5 5 5 150 15 100 70 15 5 50 50 50 30 30 15 10 Weeping Lovegrass Deertongue Sheep Fescue 5 Common Lespedeza Inoculated Tall Fescue (Turf-type) or Strong Creeping Red Fescue or Perennial Ryegrass 140 .3 1. low maintenance. 5.13 6 12/03 150 100 25 25 50 50 20 20 50 90 100 25 30 Residential Lawns Tall Fescue Perennial Ryegrass Kentucky Bluegrass Blend Tall Fescue Perennial Ryegrass Sheep Fescue Creeping Red Fescue Chewings Fescue Rough Bluegrass Kentucky Bluegrass Creeping Red Fescue Rough Bluegrass or Chewings Fescue K-31 Tall Fescue 75 35 30 45 10 lb/Ac Redtop Creeping Bentgrass Sheep Fescue Rough Bluegrass 6 Reed Canarygrass Poorly Drained Soils Certified Seed3 . Warm season grass mix and Reed Canary Grass cannot be mowed more than 4 times per year.57 1. Planting dates listed above are average for Delaware.ft. light traffic. 3. Seeding Mixtures . but performs well alone in lawns. 15 14 13 12 11 10 9 Mix No. moderate traffic tolerance. Quick stabilization of disturbed sites and waterways Remarks 1.5/1.3/1. irrigation necessary.15 1.3 0. All leguminous seed must be inoculated.3 . The maximum % of weed seeds shall be in accordance with Section 1.4 1.8 0.8/110/31-2/1 4/30 8/14 10/31 4/30 7/31 10/31 O A O O A O Add 100 lbs. 4. wildlife cover and wetland revegetation. Good erosion control. the total rate of seed should be increased by 25%. High value.4 0. Winter Rye A O A O O = Optimum Planting Period A = Acceptable Planting Period Optimum Seeding Dates 2 Monoculture.3a Seed mixes and recommended seeding dates (cont. Warm season grasses require a soil temperature of at least 50 degrees in order to germinate.Figure 3.57 0. Cool season species may be planted throughout summer if soil moisture is adequate or seeded area can be irrigated./ac. Shade tolerant. 3.15 2. and will remain dormant until then. Moderate value. traffic tolerant Shade tolerant. 1.15 0.3.23 Seeding Rate1 O O O O O A A A A A O O O O O O O O O O A A A A A O O O O O All4 Coastal Plain Piedmont 2/1. full sun. These dates may require adjustment to reflect local conditions. high maintenance. Title 3 of the Delaware Code.3 0.) 3. Well drained soils. moisture tolerant. 2.5/1. When hydroseeding is the chosen method of application. Discouraged.69 1 0. Chapter 24.72 0.4.5 2. moderate maintenance. 7.8/15. 6.69 lb/1000 sq. Winter seeding requires 3 tons per acre of straw mulch.4.1 2.57 0. All seed shall meet the minimum purity and minimum germination percentages recommended by the Delaware Department of Agriculture. Dominion. Figure 3.12.3a for detailed information on seed mixes.14 . athletic fields 7. The grass species listed in Fig. 6 6.15 14. detentions basins 2.2. Compact Perennial Rye Grass Palmer III. Cooperative Extension Service for additional information.3. Figure 3. The varieties listed above are examples of recommended varities. 9 Recreation areas. 3.3c Recommended seed varieties 6 12/03 3.4. Flyer.5 3. 13 9. Scaldis. Livingston.4 6.3 . Refer to Chapters 16 and 18 of the NRCS Field Engineering Manual for additional measures. Guardian. Monopoly. Pinnacle. Moonlight. Rebel 2000.3. Bighorn NOTES : 1. berms and dams Drainage ditches. Midnight. 4 9.4.3. Eagleton. spillways 1. dikes. Refer to Fig. borrow areas Streambanks and shorelines Utility rights-of-way 2 1. Heritage. Showcase. Jasper.2. Pick MDR Creeping Red Fescue Cindy Lou. Plantation.4. Caliber. Rebel II.Permanent Stabilization Mixtures for Various Uses Planting Mixtures by Soil Drainage Class 1 Application Residential/commercial lots 1 Well Drained Soils Poorly Drained Soils 11. Dawson. Blazer II. Titan 2. Merit.3b Seed mix selection chart RECOMMENDED SEED VARIETIES SPECIES Tall Fescue Alamo E. Crossfire. Contact University of Delaware. Haga.4 4. Safari.4 3. Ruby.3. 3 1.10. 6 1.4. 4. NOTE : Refer to NRCS critical area planting standard for additional seed mixtures.15 1.3. Freedom. Pennlawn. Comstock. Apache II. Brilliant. swales. 2.2. Crossfire. 2.14 3. Barracuda Chewings Fescue Longfellow. roadsides. 5. America. Seville. Pennfine.15 8 14. 4 1. 3. Residential open space Pond and channel banks.15 Contact plant specialist for site specific recommendations.4. Champagne.13.2 9.14 Filter strips 2.14 Steep slopes and banks. Titan 2 Kentucky Blue Grass Low Maintenance Varieties : Barirus. borrow areas Sand and gravel pits. 3 2.3. Barrington. Discovery. Unique. The seed choices listed above are the recommended varieties based on regional performance and availability. Duke. Jamestown. Salem Red Top Streaker.3a are often available in many varieties. Liberator.3. sanitary landfills Dredged material. Shenandoah. 13 Grassed waterways.10 2. spoilbanks.2. Nuglade. Coventry. Washington Shade Tolerant Varieties : Princeton. Sod not transplanted within this period shall be inspected and approved prior to its installation. delivered and installed within a period of 36 hours. but no more than 3 years old. The preferred planting period for sod is early fall (September) followed by the period between February 15 and April 30. and debris. All sod shall be uniform.3 .ADDITIONAL STANDARD AND SPECIFICATIONS FOR SODDING Definition: The establishment of grass to provide permanent stabilization on disturbed areas using sod. 5. Standard size sections of sod shall be strong enough to support their own weight and retain their size and shape when lifted from one end. b. 2. Before laying sod. plus or minus ¼ inch.4. 4.15 12/03 .Apply liming materials based on the recommendations of a soil test in accordance with the approved nutrient management plan. Lime . If a nutrient management plan is not required. torn or uneven sections will not be acceptable. Stones and clods larger than 2 inches shall also be removed. the surface shall be uniformly graded and cleared of all roots. It should be at least 1 year old. 2. When planted after October 1. Sod shall not be harvested or transplanted when moisture content (excessively dry or wet) may adversely affect its survival. 3. Surface Preparation a. at the time of cutting. apply dolomitic limestone at 6 3. Conditions Where Practice Applies Disturbed areas that require immediate and permanent vegetative cover. Sod can be laid between May 1 and August 30 with frequent supplemental watering. Surfaces that have become hard packed shall be scarified prior to laying sod. trash. Turfgrass sod shall be certified for use in the State of Delaware. Measurement for thickness shall exclude top growth and thatch. frost-heaving can be a problem if sufficient rooting has not taken place. Special Conditions 1. Sod shall be machine cut at a uniform soil thickness of ¾ inch. broken. Soil Amendments a. Sod should be harvested. Purpose: To provide immediate vegetative cover in order to stabilize soil on disturbed areas. Specifications 1. areas where sodding is the preferred means of grass establishment or areas where prompt use and aesthetics are important. brush. 6. sod should be laid with the long edges parallel to the contour. Sod shall be watered immediately after rolling or tamping until the underside of the new sod and soil surface below the sod are thoroughly wet. see Section 3. If possible. For additional information. The operations of laying.3. For additional information. c. For additional information. Lateral joints shall be staggered in a brick-like pattern.1. Apply fertilizer uniformly and incorporate into the top 4 to 6 inches of soils. In the absence of adequate rainfall. the soil shall be lightly irrigated immediately prior to laying the sod. The first row of sod shall be laid in a straight line with subsequent rows placed parallel to and tightly wedged against each other. Grass height shall be maintained between 2 and 3 inches unless otherwise specified.3 . d. 6 12/03 3. If a nutrient management plan is not required. Fertilizer . After the first week. As sodding is completed in any one section.Apply fertilizer based on the recommendations of a soil test in accordance with the approved nutrient management plan. b. Sod Installation a.4. Lime according to soil test recommendations at least once every five years. Insure that sod is not stretched or overlapped and that all joints are butted tight in order to prevent voids which would cause drying of the roots. apply 10-10-10 at the rate of 600 pounds per acre. this could make the installation prone to slump failure. c. divert runoff away from the slope until root establishment. on long slope lengths. Additional Standards and Specifications for Soil Testing.3. However. Apply limestone uniformly and incorporate into the top 4 to 6 inches of soil.1.1. with staggered joints and secured with pegs or staples. A well pegged vertical installation may be preferable under these conditions with prior approval. b. tamping and irrigating for any piece of sod shall be completed within eight hours. see Section 3. Maintenance of established sod includes fertilization in spring and fall based on soil test recommendations in accordance with an approved nutrient management plan. 3. see Section 3. d. watering shall be performed daily or as often as necessary during the first week and in sufficient quantities to maintain moist soil to a depth of 4 inches. Additional Standards and Specifications for Soil Testing.4. Sod Maintenance a. No more than 1/3 of the grass leaf shall be removed by the initial cutting or subsequent cuttings. During periods of excessively high temperature. the entire area shall be rolled or tamped to insure solid contact of roots with the soil surface.3. Never allow sod to dry out completely.4. Additional Standards and Specifications for Soil Testing.16 . b. The first mowing should not be attempted until sod is firmly rooted. 4. The sod industry generally recommends that on sloping areas where erosion might be a problem. sod shall be watered as necessary to maintain adequate moisture and insure establishment.4.the rate of 1 to 2 tons per acre. Winter seeding requires 3 tons per acre of straw mulch for proper stabilization.ft. Seed after frost through summer at a depth of 0. 6.5 1 O = Optimum Planting Period. Contact a County Extension Office for information.4. Fifty pounds per acre of Annual Lespedeza may be added to 1/2 the seeding rate of any of the above species.5 inches 1-2" sandy soils 0. DE-ESC-3. 4. 3. Good on low fertility and acid areas. Use varieties currently recommended for Delaware. Seed at 3-5 lbs.5 inches 1-2" sandy soils 1.5 O O A 1-2 inches 2-3" sandy soils 1-2 inches 2-3" sandy soils 1-2 inches 2-3" sandy soils 0. 5.5 inches 1-2" sandy soils 1-2 inches 2-3" sandy soils 0.3 Sheet 1 of 4 12/03 Date: _________________ . per acre. May be planted throughout summer if soil moisture is adequate or seeded area can be irrigated. DEPTHS AND DATES 6 Species Mix # Seeding Rate Optimum Seeding Dates Coastal Plain Certified Seed lb/Ac .5".5 inches 1-2" sandy soils 0. Warm season grasses such as Millet or Weeping Lovegrass may be used between 5/1 and 9/1 if desired. 2/14/30 2 5/18/14 8/153/1-4/30 10/31 3 All Piedmont 2 Planting Depth 5/17/31 8/110/31 10/312/1 1 Barley 125 4 O A O O A O 2 Oats 125 4 O A A O A A 3 Rye 125 4 O A O O A O 4 Perennial Ryegrass 125 4 O A O O A O 5 Annual Ryegrass 125 4 O A O O A O A 6 Winter Wheat 125 4 O A O O A O A 7 Foxtail Millet 30 PLS 0.Standard Detail & Specifications Vegetative Stabilization TEMPORARY SEEDING BY RATES. A = Acceptable Planting Period lb/1000 sq. Applicable on slopes 3:1 or less.7 O O 8 Pearl Millet 20 PLS 0. 2. Source: Delaware ESC Handbook Symbol: Detail No. 11 0. Three cultivars of Kentucky Bluegrass.46 0./ac.69 0.3 1.5/1.61 0. lb/Ac Symbol: Remarks O = Optimum Planting Period A = Acceptable Planting Period All4 Coastal Plain Piedmont 2/1. Creeping Red Rye Fescue for heavy shade./ac. Flatpea to suppress woody vegetation.23 Deertongue Sheep Fescue Common Lespedeza5 Inoculated Tall Fescue (Turf-type) or Strong Creeping Red Fescue or Perennial Ryegrass 30 30 15 0. Indian Grass and Bluestem have fluffy seeds. Poor shade tolerance.3/1.15 plus Flatpea5 Strong Creeping Red Fescue Kentucky Bluegrass Perennial Ryegrass or Redtop 15 100 70 15 5 0.23 0.ft. DE-ESC-3.11 0.weeds Managed filter strip for nutrient uptake. Creeping Red Fescue will provide erosion protection while the warm season grasses get established. Rye Germinates only in hot weather A O A A O A Add 100 Good erosion control mix lbs.7 or Coastal Panicgrass Big Bluestem Little Bluestem Indian Grass Tall Fescue (turf-type) (Blend of 3 cultivars) Tall Fescue Ky.69 0.8/110/31-2/1 4/30 8/14 10/31 4/30 7/31 10/31 A O A A O A Add 100 Good erosion control mix lbs. N fertilizer discouraged .11 plus White Clover5 3 10 10 5 5 5 150 0.07 0. O A O O A O Add 100 Suitable waterway mix.3 Sheet 2 of 4 12/03 Date: _________________ ./ac Tolerant of low fertility soils Winter Lovegrass very difficult to mow./ac Tolerant of low fertility soils Winter Good wildlife cover and food Rye O A O O A O Add 100 Good erosion control mix lbs. Rye Use Redtop for increased drought tolerance. Tolerant of low fertility soils.5 150 20 20 10 10 8 30 3. Plant with a specialized native seed drill.34 2.18 0. O O O A O O A O O A O O A O O A O A Native warm-season mixture.35 50 50 50 1. Canada Bluegrass more Winter drought tolerant.23 0.11 0.15 1. 3.2 Weeping Lovegrass 10 0. Detail No.8/15. Tall Fescue for droughty Winter conditions.07 0.46 0.4. Certified Seed3 Tall Fescue 140 lb/1000 sq.1 3.5 0.Standard Detail & Specifications Vegetative Stabilization PERMANENT SEEDING AND SEEDING DATES Seeding Mixtures Mix No. All species are native.35 0.23 0.05 Well Drained Soils 1 2 3 4 5 6 7 8 Switchgrass6.23 0.69 5 3 3 2 0.5/1.07 0.15 1. Bluegrass (Blend) Perennial Ryegrass Big Bluestem7 Indian Grass7 Little Bluestem7 Creeping Red Fescue plus one of: Partridge Pea Bush Clover Wild Indigo Showy Tick-Trefoil Source: Delaware ESC Handbook Optimum Seeding Dates 2 Seeding Rate1 . Drought tolerant. Traffic tolerant. lbs. All seed shall meet the minimum purity and minimum germination percentages recommended by the Delaware Department of Agriculture.8/15.15 1. 7. low maintenance. 3. 5. 100 25 25 50 50 20 20 50 90 2.8/110/31-2/1 4/30 8/14 10/31 4/30 7/31 10/31 O A O O A O Add 100 lbs.3 Sheet 3 of 4 12/03 Date: _________________ . Warm season grasses require a soil temperature of at least 50 degrees in order to germinate. traffic tolerant Shade tolerant.5/1.57 0. light traffic.57 1. Source: Delaware ESC Handbook Symbol: Detail No.23 Residential Lawns Tall Fescue Perennial Ryegrass Kentucky Bluegrass Blend 100 25 30 2.3 0. and will remain dormant until then.) Seeding Mixtures Mix No. irrigation necessary.72 0. the total rate of seed should be increased by 25%. 6. 150 3. When hydroseeding is the chosen method of application. but performs well alone in lawns. moisture tolerant.5/1. 1. The maximum % of weed seeds shall be in accordance with Section 1. high maintenance. Planting dates listed above are average for Delaware.5 O A O O A O Monoculture. Title 3 of the Delaware Code. Cool season species may be planted throughout summer if soil moisture is adequate or seeded area can be irrigated. Well drained soils. Certified Seed3 10 11 12 13 14 15 Remarks O = Optimum Planting Period A = Acceptable Planting Period All4 Coastal Plain Piedmont 2/1.3 0. DE-ESC-3.4 1. All leguminous seed must be inoculated. wildlife cover and wetland revegetation./ac.ft.69 1 0. These dates may require adjustment to reflect local conditions. 4.8 0. O A O O A O Shade tolerant. Winter seeding requires 3 tons per acre of straw mulch.4 0.15 2. Discouraged.Standard Detail & Specifications Vegetative Stabilization PERMANENT SEEDING AND SEEDING DATES (cont. Quick stabilization of disturbed sites and waterways Good erosion control. Poorly Drained Soils 9 Optimum Seeding Dates 2 Seeding Rate1 Tall Fescue Perennial Ryegrass Sheep Fescue Creeping Red Fescue Chewings Fescue Rough Bluegrass Kentucky Bluegrass Creeping Red Fescue Rough Bluegrass or Chewings Fescue K-31 Tall Fescue lb/Ac. moderate traffic tolerance. Winter Rye A O A O Redtop Creeping Bentgrass Sheep Fescue Rough Bluegrass Reed Canarygrass6 75 35 30 45 10 lb/1000 sq.15 0. 2. Warm season grass mix and Reed Canary Grass cannot be mowed more than 4 times per year.57 0. full sun. moderate maintenance. 1. Chapter 24.3/1.69 O A O O A O High value.1 O A O O A O O A O O A O Moderate value.4. and sediment basins. The soil surface should not be compacted or crusted. and free of large clods. 3.Apply liming materials based on the recommendations of a soil test in accordance with the approved nutrient management plan. grassed waterways.Standard Detail & Specifications Vegetative Stabilization Construction Notes: 1. 2. The seedbed should be well prepared. Mulching All mulching shall be done in accordance with detail DE-ESC-3. Lime . apply dolomitic limestone at the rate of 1 to 2 tons per acre. Source: Delaware ESC Handbook Symbol: Detail No. they will be mixed on site and the seeding shall be done immediately and without interruption. 4. and other objectionable material. DE-ESC-3. For a permanent stabilization. Apply fertilizer uniformly and incorporate into the top 4 to 6 inches of soils. apply a formulation of 10-10-10 at the rate of 600 pounds per acre. uniform. install needed erosion and sediment control practices such as diversions. All seed will be applied at the recommended rate and planting depth. loose.5. Seed that has been broadcast should be covered by raking or dragging and then lightly tamped into place using a roller or cultipacker. Prior to seeding. Fertilizer . drill. If a nutrient management plan is not required. b. Seeding a.4. If a nutrient management plan is not required. cultipacker seeder or hydroseeder. Site Preparation a. Soil Amendments a. Seedbed Preparation It is important to prepare a good seedbed to insure the success of establishing vegetation. If hydroseeding is used and the seed and fertilizer is mixed. Apply seed uniformly with a broadcast seeder. dikes. select a mixture from Sheet 1 .Apply fertilizer based on the recommendations of a soil test in accordance with the approved nutrient management plan. b. c. b. Final grading and shaping is not necessary for temporary seedings. grade stabilization structures.3 Sheet 4 of 4 12/03 Date: _________________ .4. Apply limestone uniformly and incorporate into the top 4 to 6 inches of soil. rocks. berms. 5. select a mixture from Sheet 2 or Sheet 3 depending on the conditions. For temporary stabilization. 2. estuaries. vegetation. Scope: This standard applies to measures used to stabilize and protect the banks of streams. To reduce sediment loads causing downstream damages and pollution. To prevent the loss of land or damage to utilities. or groins are to be no higher than 3 ft. lakes. ice. To maintain the capacity of the channel. All revetments. estuaries. or upland erosion control practices and where failure of structural measures will not create a hazard to life or result in serious damage to property. or excavated channels for one or more of the following purposes: 1. To control channel meander that would adversely affect downstream facilities. estuaries. 4. lakes. above mean high water.4. Effects on the water table of adjoining fields. or debris or to damage from livestock or vehicular traffic.STANDARD AND SPECIFICATIONS FOR STREAMBANK AND SHORELINE STABILIZATION Definition: Using vegetation or structures to stabilize and protect banks of streams. Condition where Practice Applies: This practice applies to natural or excavated channels where the streambanks are susceptible to erosion from the action of water. or in nontidal areas. 3. It also applies to controlling erosion on shorelines where the problem can be solved with relatively simple structural measures. Purpose: To stabilize or protect banks of streams. or excavated channels against scour and erosion. and ground water recharge. and excavated channels. infiltration. 3. deep percolation. bulkheads. above mean high tide or. 6 3. no higher than 3 ft. buildings. lakes. Planning Considerations Water Quantity 1.4 . or other facilities adjacent to the banks. or To improve the stream for recreation or as a habitat for fish and wildlife. It does not apply to erosion problems on main ocean fronts and similar areas of complexity. Effects on downstream flows and aquifers that affect other uses and users. Effects on the interflow discharge into streams. 4. especially on volumes and rates of runoff. 5. Effects on the water budget.1 12/03 . roads. 2. Effects on erosion and movement of sediment. However. Structural measures must be effective for the design flow and be able to withstand greater floodswithout serious damage. properly underlaid with a filter blanket. Effects of construction and vegetation establishment on quality. 7. practitioners are cautioned against designing streambank and shoreline stabilization measures without appropriate expertise. and existing structures.4. 4. measures for streambank and shore protection must be installed according to a plan and adapted to the specific site. hydraulic characteristics.4 . 3. and sediment-attached and dissolved substances. 3. Changes in channel alignment shall be made only after an evaluation of the effect on the land use. 5. Placed or dumped heavy stone. and soluble and sediment-attached substances carried by runoff and streamflow. Reduction of the slope of streambanks to provide a suitable condition for vegetative protection or for the installation of structural bank protection. Design Criteria Because each reach of a channel. They shall also be designed to avoid an increase in erosion downstream of planned measures. debris. Streambank Protection Measures The following is a partial list of elements that may be included in a plan for streambank protection. before any permanent type of bank protection can be considered feasible. stumps. debris. The grade must be controlled. 6 12/03 3. Therefore. Short-term and long-term effects on wetlands and water-related wildlife habitats. especially on areas that are susceptible to infrequent inundation. 2. 4. lake. interdependent water disposal systems. The Natural Resources Conservation Service (NRCS) has developed guidelines for streambank and shoreline stabilization in Chapter 16 of their Engineering Field Manual (refer to Design Guide 3 of this handbook). 2. and bars that force the streamflow into the streambank shall be an initial element of the work. Vegetative protection shall be considered on the upper parts of eroding banks. 3. if necessary. applying these guidelines often requires specialized expertise in hydrology. unless the protection can be safely and economically constructed to a depth well below the anticipated lowest depth of bottom scour. Protective measures to be applied shall be compatible with improvements planned or being carried out by others. 6. to provide armor protection for streambanks. Figure 3. Removal of fallen trees. 6.2 . Removal of trees and brush that adversely affect the growth of desirable bank vegetation. 4. Designs for streambanks shall be according to the following principles: 1. potentially worse than the original problem.4. geotechnology and the plant sciences. Streambank protection shall be started at a stabilized or controlled point and ended at a stabilized or controlled point on the stream. 2. Effects on the visual quality of onsite and downstream water resources. Effects of changes in water temperatures. fallen trees. minor ledge outcroppings. 5. Filtering effects of vegetation on movement of sediment. Needed channel clearing to remove stumps. either by natural or artificial means.4a illustrates many of these measures and summarizes their key features.Water Quality 1. and sand and gravel bars that may cause local current turbulence and deflection. hydraulics. 1. A poor design can lead to serious consequences. geomorphology. or estuary is unique. Groin systems (timber or concrete). 4. Special attention shall be given to maintaining or improving habitat for fish and wildlife. Considerations shall be given to the use of construction materials. Deflectors constructed of posts. 2. It is therefore impossible to develop a set of standard details and specifications which would meet the requirements of each situation. and other site development elements that minimize visual impacts and maintain or complement existing landscape uses such as pedestrian paths. However. End sections shall be adequately bonded to existing measures or terminate in stable areas. Design water surface shall be mean high tide or in nontidal areas the mean high water. streambank and shoreline stabilization requires site specific plans. etc. Slope characteristics below the waterline shall be representative of the slope for a minimum of 50 ft (15 m) distance from the shore.5. such as fences. Design Guide 3 does contain generic details of various measures which may serve as the basis for site specific plans.4. grading practices. vegetation.4 . Figure 3. concrete block). Standard Details and Specifications As mentioned above. Revetments (prefabricated slope protection blocks. 2.3 12/03 . 7. brush. or the materials that project into the stream to protect banks at curves and reaches subjected to impingement by high velocity currents.4. 3. concrete. 6 3. Control of surface runoff and internal drainage shall be considered in the design and installation of all shore protection measures. buffers. soil cement). Treatment depends on soil type and the slope characteristics both above and below the waterline. Artificial obstructions. Pervious or impervious structures built on or parallel to the stream to prevent scouring streamflow velocities adjacent to the streambank. 3. climate controls. 2. 6. rock. Vegetation of the type that will grow across or along the waterline. to protect vegetation needed for streambank protection or to protect critical areas from damage from stock trails or vehicular traffic. piling. Designs for shoreline protection shall be according to the following principles: 1.4a illustrates many of these measures and summarizes their key features. riprap. Shoreline Protection Measures The following is a partial list of protection measures that may be used. Other Considerations 1. 4. fencing. 1. Bulkheads (timber. 4a. Sheet 1 of 8.4. and Practices 6 12/03 3. Stream Corridor Restoration: Principles Processes.4 . Streambank and shoreline stabilization practices Source: USDA-NRCS.4 .4.Figure 3. 4a. Stream Corridor Restoration: Principles Processes.4a.4.Figure 3.5 6 12/03 . Sheet 2Figure 3.4 . and Practices 3. Sheet 2 of 8.4. Streambank and shoreline stabilization practices Source: USDA-NRCS.4. Sheet 3 of 8.Figure 3.4. Stream Corridor Restoration: Principles Processes.4a.4 .6 . Streambank and shoreline stabilization practices Source: USDA-NRCS.4. and Practices 6 12/03 3. 4. Stream Corridor Restoration: Principles Processes. Streambank and shoreline stabilization practices Source: USDA-NRCS. and Practices 6 3.Figure 3.4a.4 . Sheet 4 of 8.4.7 12/03 . Streambank and shoreline stabilization practices Source: USDA-NRCS. Sheet 5 of 8. and Practices 6 12/03 3.4.4 .8 .Figure 3.4a. Stream Corridor Restoration: Principles Processes.4. Sheet 6 of 8. Stream Corridor Restoration: Principles Processes.4.Figure 3.4 .4. Streambank and shoreline stabilization practices Source: USDA-NRCS.4a.9 6 12/03 . and Practices 3. 4. Sheet 7 of 8. Streambank and shoreline stabilization practices Source: USDA-NRCS.4 .10 .4.Figure 3.4a. Stream Corridor Restoration: Principles Processes. and Practices 6 12/03 3. Sheet 8 of 8.11 6 12/03 .4.Figure 3. Stream Corridor Restoration: Principles Processes.4a.4.4 . and Practices 3. Streambank and shoreline stabilization practices Source: USDA-NRCS. 6 12/03 3.4 .12 .4.This page left intentionally blank. berms. Mulch helps to conserve moisture.4. or 70 to 90 pounds (two bales) per 1. thistles. apply mulch in a two-step process. Purpose: To protect the soil surface from the forces of raindrop impact and overland flow.Straw shall be unrotted small grain straw applied at the rate of 1-1/2 to 2 tons per acre. Materials and Amounts a. increase the application rate of nitrogen fertilizer by 20 pounds of N per acre (200 pounds of 10-10-10 or 66 pounds of 30-0-0 per acre). reduce runoff and erosion. prevent soil crusting and promote the establishment of desired vegetation. For maximum performance. Step One: Apply seed and soil amendments at required rates. hydraulically applied mulches may be applied in a one-step process where all components may be mixed together in single tank loads. Step Two: Apply mulch at required rates. Mulching Procedures 1.Apply at the rate of approximately 6 tons per acre or 275 pounds per 1. Straw . Wood chips . Spread mulch uniformly by hand or mechanically. Site Preparation Prior to mulching.000 square feet sections and place 70-90 pounds (two bales) of mulch in each section. These are particularly well suited for utility and road rights-of-way.1 6/05 . grade stabilization structures.STANDARD AND SPECIFICATIONS FOR MULCHING Definition: The application of a protective layer of straw or other suitable material to the soil surface. install any needed erosion and sediment control practices such as diversions. The primary purpose of mulching is to provide protection for newly seeded disturbed areas.000 square feet when available and when feasible. b. 6 3. control weeds. and quackgrass. divide area into approximately 1.5 . it can also be used for stand-alone protection of the soil surface under adverse weather conditions when seed germination could be jeopardized. However. Consult with the manufacturer for further details. If wood chips are used. channels and sediment basins. For uniform distribution of hand spread mulch. Conditions Where Practice Applies: Mulching can be used at anytime where protection of the soil surface is desired.000 square feet. Johnsongrass. Depending on site conditions. Mulch materials shall be relatively free of weeds and shall be free of noxious weeds such as. Do not apply to saturated soils. Apply from opposing directions to achieve optimum soil coverage. 3. c. Refer to Figure 3. A bonded fiber matrix (BFM) consists of long strand. Hydraulic mulches shall be applied with a viable seed and at manufacturer’s recommended rates. v. BFMs shall contain no paper (cellulose) mulch but may contain small percentages of synthetic fibers to enhance performance. Hydraulically applied mulch -The following conditions apply to hydraulically applied mulch: i. b. Curing times may be accelerated in high temperature. b. Minimum curing temperature is 400 F (40 C). iv. d. or if precipitation is anticipated within 24-48 hours. ii. Materials within this category shall only be used when hydraulically applied mulch has been specified for use on the approved Sediment and Stormwater Plan. iv. is packaged for sale as a hydraulic mulch for use with hydraulic seeding equipment. All components of the hydraulically applied mulches shall be pre-packaged by the manufacturer to assure material performance. The paper component must consist of specially prepared paper that has been processed to a uniform fibrous state and is packaged for sale as a hydraulic mulch for use with hydraulic seeding equipment. Step Two – Mix and apply mulch at manufacturers recommended rates over freshly seeded surfaces. Blended fiber mulch shall consist of any hydraulic mulch that contains greater than 30% paper fiber.2 . Apply product to geotechnically stable slopes that have been designed and constructed to divert runoff away from the face of the slope.4. During the spring (March 1 to May 31) and fall (September 1 to November 30) seasons. Wood fiber mulch shall consist of specially prepared wood that has been processed to a uniform state. low humidity conditions on dry soils. specially prepared wood fibers that have been processed to a uniform state held together by a water resistant bonding agent. Hydraulically applied mulches and additives shall be mixed according to manufacturers recommendations. 6 6/05 e. Definitions: a. Application: a.c. and consists of a minimum of 70% virgin or recycled wood fiber combined with 30% paper fiber and additives. hydraulic mulches may be applied in a one-step process where all components are mixed together in single-tank loads. Increased rates may be necessary based on site conditions. During the summer (June 1 to August 31) and winter (December 1 to February 28) seasons. but must be done per manufacturers recommendations to ensure the proper results. c.5a for conditions and limitations of use for each of the above categories of hydraulic mulch. iii.5 . the following two-step process is required: Step One– Mix and apply seed and soil amendments with a small amount of mulch for visual metering. It is recommended that the product be applied from opposing directions to achieve optimum soil coverage. Field mixing of the mulch components is acceptable. or supplemental approval from the plan approval agency has been obtained in writing for a specific area. d.4. The best results and more rapid curing are achieved at temperatures exceeding 600 F (150 C). c. Nettings .Applications of liquid mulch binders should be heavier at edges. Liquid mulch binders . This may be done by one of the following methods.A crimper is a tractor drawn implement designed to punch and anchor mulch into the top two (2) inches of soil. Anchoring mulch .vi. Tracking is used primarily on slopes 3:1 or steeper and should be done up and down the slope with cleat marks running across the slope. Paper fiber . and the mixture shall contain a maximum of 50 lbs. and cost. Recommended application rates are for informational purposes only. d.5 . 2. Install and secure according to the manufacturers recommendations. This practice affords maximum erosion control but is limited to flatter slopes where equipment can operate safely.4. On sloping land. crimping should be done on the contour whenever possible.Mulch must be anchored immediately to minimize loss by wind or water. Tracking .Synthetic or organic nettings may be used to secure straw mulch. Conformance with this standard and specification shall be performance-based and requires 100% soil coverage. a.3 6/05 . and at crests of banks and other areas where the mulch will be moved by wind or water. of wood cellulose fiber per 100 gallons. The use of synthetic binders is the preferred method of mulch binding and should be applied at the rates recommended by the manufacturer. b. in valleys. All other areas should have a uniform application of binder. Crimping . e.The fiber binder shall be applied at a net dry weight of 750 lbs/ac. erosion hazard. 6 3. Any areas with bare soil showing shall be top dressed until full coverage is achieved. depending upon size of area. The wood cellulose fiber shall be mixed with water.Tracking is the process of cutting mulch (usually straw) into the soil using a bulldozer or other equipment that runs on cleated tracks. 4. 1 to Feb. min. min. BFM @ 3500-4000 lbs/ac.) OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK Sept. Stabilization Matting** Wood Fiber @ 2000 lbs/ac. ***Note: Straw applied on slopes greater than 33% must be netted (this does not apply to topsoil stockpiles).4. Stabilization Matting** Wood Fiber @ 2500-3000 lbs/ac. min. BFM @ 3000-3500 lbs/ac. min Straw @ 2 Tons/ac. OK = Acceptable to use during this time period. Straw @ 2 Tons/ac. min. Straw @ 2 Tons/ac. min. Straw @ 2 Tons/ac. BFM @ 3000 lbs/ac. Rate* MULCHING MATERIAL SELECTION GUIDE . min. 30 * Note: Manufacturers Recommended Rates for informational purposes only.6 of the Delaware ESC Handbook. Performance standard requires 100% soil coverage. 1 to Nov.5a Mulching material selection guide 6 6/05 3. Straw @ 2 Tons/ac. Stabilization Matting** Wood Fiber @ 2500-3000 lbs/ac. min.4 33% and up 25% to 33% 11% to 24. ** Note: Stabilization Matting must be applied in accordance with Section 3.9% Less than 2% Percent Slope xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxx OK OK xxxxxxxxxxxxxxxxxx OK OK Dec. min.) OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK (< 1 ac. All application rates are minimums Blended Fiber @ 2000 lbs/ac. Min.Figure 3. min. min.9% 6% to 10. Stabilization Matting** BFM @ 4000-4500 lbs/ac.4. BFM @ 3500-4000 lbs/ac. Stabilization Matting** Wood Fiber @ 2000-2500 lbs/ac. minimum Wood Fiber @ 2000 lbs/ac. min. Straw @ 2 Tons/ac.*** Stabilization Matting** Type of Mulch / App.5 .9% 2% to 5. 31 xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxx OK OK xxxxxxxxxxxxxxxxxx OK OK March 1 to May 31 OK (< 1 ac. min. 28(29) June 1 to Aug. xxx = Not acceptable to use during this time period. min. min. BFM @ 4000 lbs/ac. min. These are particularly well suited for utility and road rights-of-way. Materials within this category shall only be used when hydraulically applied mulch has been specified for use on the approved Sediment and Stormwater Plan. b. increase the application rate of nitrogen fertilizer by 20 pounds of N per acre (200 pounds of 10-10-10 or 66 pounds of 30-0-0 per acre). c. Wood chips . BFMs shall contain no paper (cellulose) mulch but may contain small percentages of synthetic fibers to enhance performance. c. b. A bonded fiber matrix (BFM) consists of long strand.Apply at the rate of approximately 6 tons per acre or 275 pounds per 1. Hydraulically applied mulches and additives shall be mixed according to manufacturers recommendations. Straw . iii. Hydraulically applied mulch -The following conditions apply to hydraulically applied mulch: i. is packaged for sale as a hydraulic mulch for use with hydraulic seeding equipment. or supplemental approval from the plan approval agency has been obtained in writing for a specific area. Spread mulch uniformly by hand or mechanically.5a for conditions and limitations of use for each of the above categories of hydraulic mulch. iv. DE-ESC-3. Source: Symbol: Detail No.Straw shall be unrotted small grain straw applied at the rate of 1-1/2 to 2 tons per acre. d. ii. and consists of a minimum of 70% virgin or recycled wood fiber combined with 30% paper fiber and additives. or 70 to 90 pounds (two bales) per 1. Wood fiber mulch shall consist of specially prepared wood that has been processed to a uniform state. but must be done per manufacturers recommendations to ensure the proper results. The paper component must consist of specially prepared paper that has been processed to a uniform fibrous state and is packaged for sale as a hydraulic mulch for use with hydraulic seeding equipment.Standard Detail & Specifications Mulching 1. Hydraulic mulches shall be applied with a viable seed and at manufacturer’s recommended rates. Increased rates may be necessary based on site conditions. and quackgrass.000 square feet. For uniform distribution of hand spread mulch.000 square feet when available and when feasible.5 Delaware ESC Handbook Sheet 1 of 3 6/05 Date: _________________ . Refer to Figure 3. divide area into approximately 1.4. Mulch materials shall be relatively free of weeds and shall be free of noxious weeds such as. Materials and Amounts a. Field mixing of the mulch components is acceptable. Blended fiber mulch shall consist of any hydraulic mulch that contains greater than 30% paper fiber. specially prepared wood fibers that have been processed to a uniform state held together by a water resistant bonding agent.000 square feet sections and place 70-90 pounds (two bales) of mulch in each section. If wood chips are used. Definitions: a. iv. thistles. Johnsongrass.4. All components of the hydraulically applied mulches shall be pre-packaged by the manufacturer to assure material performance. b. Minimum curing temperature is 400 F (40 C). a. During the summer (June 1 to August 31) and winter (December 1 to February 28) seasons. The wood cellulose fiber shall be mixed with water. Paper fiber .Tracking is the process of cutting mulch (usually straw) into the soil using a bulldozer or other equipment that runs on cleated tracks. Tracking is used primarily on slopes 3:1 or steeper and should be done up and down the slope with cleat marks running across the slope. DE-ESC-3. c. in valleys. Conformance with this standard and specification shall be performance-based and requires 100% soil coverage. On sloping land.4. and at crests of banks and other areas where the mulch will be moved by wind or water.A crimper is a tractor drawn implement designed to punch and anchor mulch into the top two (2) inches of soil. of wood cellulose fiber per 100 gallons. Curing times may be accelerated in high temperature. It is recommended that the product be applied from opposing directions to achieve optimum soil coverage. d. or if precipitation is anticipated within 24-48 hours. c. e. Any areas with bare soil showing shall be top dressed until full coverage is achieved. Apply product to geotechnically stable slopes that have been designed and constructed to divert runoff away from the face of the slope.5 Delaware ESC Handbook Sheet 2 of 3 6/05 Date: _________________ . crimping should be done on the contour whenever possible. Install and secure according to the manufacturers recommendations. Crimping .Standard Detail & Specifications Mulching v. and the mixture shall contain a maximum of 50 lbs. and cost. Nettings . depending upon size of area. Source: Symbol: Detail No. Application: a. hydraulic mulches may be applied in a one-step process where all components are mixed together in single-tank loads. Recommended application rates are for informational purposes only. The best results and more rapid curing are achieved at temperatures exceeding 600 F (150 C).Synthetic or organic nettings may be used to secure straw mulch. 2. The use of synthetic binders is the preferred method of mulch binding and should be applied at the rates recommended by the manufacturer. low humidity conditions on dry soils. erosion hazard. Anchoring mulch . e.Applications of liquid mulch binders should be heavier at edges. Liquid mulch binders . This may be done by one of the following methods. This practice affords maximum erosion control but is limited to flatter slopes where equipment can operate safely. During the spring (March 1 to May 31) and fall (September 1 to November 30) seasons. Step Two – Mix and apply mulch at manufacturers recommended rates over freshly seeded surfaces. All other areas should have a uniform application of binder. b. Apply from opposing directions to achieve optimum soil coverage.Mulch must be anchored immediately to minimize loss by wind or water. Tracking .The fiber binder shall be applied at a net dry weight of 750 lbs/ac. vi. Do not apply to saturated soils. the following two-step process is required: Step One– Mix and apply seed and soil amendments with a small amount of mulch for visual metering. d. minimum Wood Fiber @ 2000 lbs/ac. min. Stabilization Matting** Wood Fiber @ 2000 lbs/ac. OK = Acceptable to use during this time period. BFM @ 3500-4000 lbs/ac. 1 to Nov. min. Straw @ 2 Tons/ac. BFM @ 3000 lbs/ac. Straw @ 2 Tons/ac. min.) OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK (< 1 ac.6 of the Delaware ESC Handbook. 31 xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxx OK OK xxxxxxxxxxxxxxxxxx OK OK March 1 to May 31 OK (< 1 ac. Stabilization Matting** BFM @ 4000-4500 lbs/ac.4.9% 6% to 10. Straw @ 2 Tons/ac.Source: Symbol: 33% and up 25% to 33% 11% to 24. min. min. min.*** Stabilization Matting** * Type of Mulch / App. min.4. min. Performance standard requires 100% soil coverage. 1 to Feb. Stabilization Matting** Wood Fiber @ 2500-3000 lbs/ac. Rate MULCHING MATERIAL SELECTION GUIDE Standard Detail & Specifications Mulching Detail No. Straw @ 2 Tons/ac. min. min. Min. Straw @ 2 Tons/ac. ** Note: Stabilization Matting must be applied in accordance with Section 3. DE-ESC-3.9% Less than 2% Percent Slope xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx OK OK OK xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxx OK OK xxxxxxxxxxxxxxxxxx OK OK Dec. 28(29) June 1 to Aug. min. All application rates are minimums Blended Fiber @ 2000 lbs/ac. min. 30 * Note: Manufacturers Recommended Rates for informational purposes only. BFM @ 3500-4000 lbs/ac. min Straw @ 2 Tons/ac. BFM @ 4000 lbs/ac. Stabilization Matting** Wood Fiber @ 2500-3000 lbs/ac. xxx = Not acceptable to use during this time period. min. min. min. Stabilization Matting** Wood Fiber @ 2000-2500 lbs/ac.) OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK Sept. ***Note: Straw applied on slopes greater than 33% must be netted (this does not apply to topsoil stockpiles).5 Sheet 3 of 3 6/05 Date: _________________ .9% 2% to 5. BFM @ 3000-3500 lbs/ac. Source: Symbol: Detail No.Standard Detail & Specifications Portable Sediment Tank This page left intentionally blank. 12/03 Date: _________________ . Care must be taken to choose the type of material which is most appropriate for the specific needs of a project.1 12/03 . The mulch material may be sandwiched between the netting or the netting may be intertwined 6 3. With the large selection of materials available today and constant improvements in the technology. some types of soil stabilization mats are also used to raise the maximum permissible velocity of turf grass linings in vegetated channels by reinforcing the turf to resist erosive forces during storm events. it is impossible to cover them all with this standard and specification. Conditions Where Practice Applies: Stabilization mats are recommended for the following conditions : 1. These materials have been improved to the point that they are now being used in many applications were structural linings would have been required in the past. 3. channel or shoreline.6 . In areas where the forces of wind prevent standard mulching practices from remaining until vegetation becomes established. Purpose: To aid in controlling erosion on critical areas by providing a microclimate which protects young vegetation and promotes its establishment.4. Planning Considerations: Stabilization mats can be applied to problem areas to aid in the initial establishment of vegetation and protect the soil from erosion due to high velocity stormwater runoff. In addition. the designer should always consult the manufacturer's recommendations for final selection and design. steep slopes where erosion hazard is high and planting is likely to be too slow in providing adequate protective cover. Selection Guidelines: Stablization mats generally fall under one of two categories: Mulching These mats are typically combination blankets consisting of plastic netting and some type of natural organic or man-made mulch. Although some general guidelines are provided. nor to keep it current. 2.STANDARD AND SPECIFICATIONS FOR STABILIZATION MATTING Definition: The installation of a protective covering on a prepared planting area of a steep slope. In vegetated channels where the velocity of design flow exceeds the allowable velocity for vegetation alone. 4. On streambanks or tidal shorelines where moving water is likely to wash out new plantings. On short. 4. Planing off excess stormwater runoff. Refer to Appendix A-4. 3. Permanent materials must be used for design shear stresses equal to or greater than 2 psf. 3. Stabilization Matting Application Guide for recommendations for appropriate material selection. Benefits of these mats include: 1. For maximum design shear stresses less than 2 psf. Allows the use of vegetated linings under conditions which would normally require concrete or riprap. Design Criteria: 1. Slope stability . Once the hydraulic design has been completed. Stronger and faster germination of grasses and legumes.6 . thus becoming a growth medium for the development of roots. For slope stability problems. Reinforcement mats are used in stormwater conveyance channels as well as to stabilize slopes. it acts with the vegetative root system to form an erosion resistant cover which resists hydraulic lift and shear forces. refer to Appendix A-4. 4.Stabilization matting is required on disturbed slopes steeper than 3:1. 6 12/03 3.with the mulch. 5. 2. Thermal consistency and moisture retention for seedbed area. 2. In either case. these mats are usually intended to degrade as vegetation becomes established. 4. Jute mesh and similar products may also act as stabilization mats. can improve the geotechnical performance of the native soil. Reinforcement Mats in this class typically consist of a non-degradable. Stabilization Matting Application Guide for recommendations for appropriate material selection. When embedded in the soil within stormwater channels. a temporary material may be used.Design for channel stabilization shall be based on the tractive force method (refer to Design Guide 1). 2. forming continuous anchorage for surface growth and promoting enhanced energy dissipation. The benefits of these types of stabilization mats include: 1. Traps entrained soil in stormwater runoff and allows it to fill the matrix.2 . This configuration provides a matrix for root growth where the matting becomes entangled and penetrated by roots. Prevention of sloughing of topsoil added to steeper slopes. Channel stability . Protection of the seed and soil from raindrop impact and subsequent displacement. 3-dimensional plastic structure which can be filled with soil prior to planting. SM-S DE-ESC-3. When mats must be spliced down the slope.1 Sheet 1 of 2 6/05 Date: _________________ . place mats end over end (shingle style) with approx. The edges of parrallel mats must be stapled with approx. 4. Symbol: Detail No. and seed. Roll the mats (A) down or (B) horizontally across the slope. Source: Adapted from North American Green. 12" apart. 5. 5 Perspectiv erspectivee Construction Notes: 1. fertilizer. 3.4. Staple through overlapped area. approx. Prepare soil before installing matting. Backfill and compact trench after stapling.Standard Detail & Specifications Stabilization Matting . Inc. 2" overlap. including application of lime. 4" overlap.Slope 4 3B 3A 2 1 Note: Use manufacturer's recommendations for stapling patterns for slope installations. Begin at the top of the slope by anchoring the mat in a 6" deep X 6" wide trench.6. 2. 4. Yd. 3.Standard Detail & Specifications Stabilization Matting . 1. SM-S DE-ESC-3. 4' 10" NOTE: These patterns are provided for general guidance only. Symbol: Detail No.75 Staples per Sq. Inc.2 Staples per Sq. Yd. 20" E 3. 2' 2' 4' 4' 20" 3' 3' D C 1. Yd.Slope 3' 3' 6' 6' 3' 3' 1 1/2' A B 0. Yd.75 Staples per Sq.6.5 Staples per Sq. Stapling P atterns Patterns Source: Adapted from North American Green. They shall not be used as a substitute for manufacturer's recommendations.1 Sheet 2 of 2 6/05 Date: _________________ .7 Staples per Sq. Yd. Standard Detail & Specifications Stabilization Matting .2 Sheet 1 of 3 6/05 Date: _________________ . Projected waterline C. Inc. Use manufacturer's recommendations for stapling patterns for channel installations.6.Channel 2 3 6 5 1 7 8 4 Perspectiv erspectivee A CRITICAL POINTS B C A. Source: Adapted from North American Green. Overlaps and seams B. SM-C DE-ESC-3. Channel bottom/side slope vertices Note: Horizontal staple spacing should be altered if necessary to allow staples to secure the critical points along the channel surface. Symbol: Detail No.4. 6. Backfill and compact the trench after stapling.6.4. 5. In high flow channel applications. Mats on side slopes must be overlapped 4" over the center mat and stapled. Place a second row 4" below the first row in a staggered pattern. Place mats end over end (shingle style) with a 6" overlap.Standard Detail & Specifications Stabilization Matting .Channel Construction Notes: 1. 4. and seed. 3. use a double row of staggered staples 4" apart to secure mats. Use a row of staples 4" apart over entire width of the channel. Symbol: Detail No. Inc. including application of lime. 8. Source: Adapted from North American Green. Full Length edge of mats at top of side slopes must be anchored in 6" deep X 6" wide trench. 7. The terminal end of the mats must be anchored in a 6" X 6" wide trench. Prepare soil before installing matting. a staple check slot is recommended at 30 to 40 foot intervals. backfill and compact the trench after stapling. SM-C DE-ESC-3. fertilizer. 2.2 Sheet 2 of 3 6/05 Date: _________________ . Begin at the top of the channel by anchoring the mat in a 6" deep X 6" wide trench. Roll center mat in direction of water flow on bottom of channel. Backfill and compact the trench after stapling. SM-C DE-ESC-3.6. 3.7 Staples per Sq. Symbol: Detail No.Channel 3' 3' 6' 6' 3' 3' 1 1/2' A B 0.2 Staples per Sq. Inc. 20" E 3. Yd. Yd.75 Staples per Sq.75 Staples per Sq. Yd.2 Sheet 3 of 3 6/05 Date: _________________ .4. Stapling P atterns Patterns Source: Adapted from North American Green. They shall not be used as a substitute for manufacturer's recommendations.5 Staples per Sq. 4' 10" NOTE: These patterns are provided for general guidance only. Yd.Standard Detail & Specifications Stabilization Matting . Yd. 1. 2' 2' 4' 4' 20" 3' 3' D C 1. Standard Detail & Specifications Stabilization Matting . 6/05 Date: _________________ . Source: Symbol: Detail No.Channel This page left intentionally blank. sidewalk or parking area.7 . it shall be done on an area stabilized with aggregate which drains into an approved sediment trapping device. Purpose: To prevent site access points from becoming sediment sources. When necessary. alley.) Maintenance Criteria The entrance shall be maintained in a condition which will prevent tracking of sediment onto public rights-of-way or streets. Geotextile Fabric Geotextiles used for stabilized construction entrances shall be Type GS-1 (see Appendix A-3. wheels must be cleaned to remove sediment prior to entrance onto public rights-of-way. or washed onto public rights-of-way must be removed immediately. or watercourses. Conditions Where Practice Applies: A stabilized construction entrance shall be used at all points of construction ingress and egress.STANDARD AND SPECIFICATIONS FOR STABILIZED CONSTRUCTION ENTRANCE Definition: A stabilized pad of aggregate on a geotextile fabric base located at any point where traffic will be entering a construction site to or from a public right-of-way. When washing is required. 6 3. ditches.1 12/03 . All sediment spilled. Design Criteria See Standard Detail. All sediment shall be prevented from entering storm drains.4. street. This may require periodic top dressing with additional aggregate. dropped. 7 . 6 12/03 3.This page left intentionally blank.2 .4. Type GS-1 geotextile fabric Section A-A (Std. 10' min.) Source: Adapted from VA ESC Handbook Symbol: Detail No.Standard Detail & Specifications Stabilized Construct. A Provide positive drainage to sediment trapping device Plan 50' min. 10' min. pave Culvert pipe (as needed) Profile 10' min.4. Entrance 50' min. 3" min. pave 10' min. 3" min. Wash rack (optional) A 10' min.7 Sheet 1 of 2 12/03 Date: _________________ . 3' GS-I geotextile 6" min. DE #3 Stone Edge exist. Exist. SCE DE-ESC-3. grnd Mountable berm (as needed) Exist. placed over the entire area prior to placing of stone. but not less than the full width at points where ingress or egress occurs. Entrance Equipment wheel track + 2' Metal bars set in reinforced conc. it shall be done on an area stabilized with stone and which drains into an approved sediment trapping device. Width .Type GS-I. Stone size . Thickness .As required. Inspection . When washing is required.All surface water flowing or diverted toward construction entrances shall be piped across the entrance. 3. 8. If piping is impractical. This may require periodic top dressing with additional stone as conditions demand and repair and/or cleanout of any measures used to trap sediment. SCE DE-ESC-3. 5. Washing . may be substituted) Provide space for drainage Section A-A (Opt. washed or tracked onto public rights-of-way must be removed immediately.Standard Detail & Specifications Stabilized Construct. Source: Adapted from VA ESC Handbook Symbol: Detail No. dropped.Vehicle wheels shall be cleaned to remove sediment prior to entrance onto public rights-ofway. timber mats or other approved equiv.4.Ten (10) foot minimum. 4.Periodic inspection and needed maintenance shall be provided after each rain. 2.) Construction Notes: 1.Not less than size (6) inches.Use DE #3 stone. 9. 7. but not less than 50 feet (except on a single residence lot where a 30 foot minimum length would apply). All sediment spilled. (traffic bearing grates. a mountable berm with 5:1 slopes will be permitted.The entrance shall be maintained in a condition which will prevent tracking or flowing of sediment onto public rights-of-way. Geotextile .7 Sheet 2 of 2 12/03 Date: _________________ . Surface Water . Length . 6. Maintenance . Traffic should be kept off these areas once they have been treated. 4. Calcium Chloride . Chisel-type plows produce the best results.4. See DE-ESC-3. Tillage . 6 3.Solid board fences.See Section 3. Asphalt-based materials are no longer accepted. snow fences. Purpose: To prevent or reduce the movement of dust from disturbed soil surfaces that may create health hazards. traffic safety problems and off-site damage.This is an emergency temporary practice that will scarify the soil surface and prevent or reduce the amount of blowing dust until a more appropriate solution can be implemented.1 12/03 .3.STANDARD AND SPECIFICATIONS FOR DUST CONTROL Definition: Controlling dust blowing and movement on construction sites and roads. Standard Detail and Specification for Dust Control for some typical application rates. 2.5.5. Adhesives . The tillage operation should begin on the windward side of the site. 7. Under certain conditions. This practice can be particulary effective for road construction.Use on mineral soils only (not effective on muck soils). hay bales an similar material can be used to control air currents and soil blowing. Mulches . 3. some of the chemicals used for dust control may also be used for bare soil stabilization in situations in which the introduction of organic materials would be undesirable.4. Barriers . Standard and Specifications for Temporary Vegetative Stabilization. such as road beds and structural fill.4. Conditions Where Practice Applies This practice is applicable to areas subject to dust blowing and movement where on and off-site damage is likely to occur if dust is not controlled. Vegetation . These are generally synthetic materials that are applied to the soil surface to act as binding agents.See Section 3. Types of Temporary Methods 1. 6. Standard and Specifications for Mulching. The site should be sprinkled with water until the surface is moist and repeated as needed. Sprinkling .This is the most commonly used dust control practice. but not so high as to cause water pollution or plant damage.Can be applied as flakes or granular material with a mechanical spreader at a rate that will keep the soil surface moist. Can be reapplied as necessary. 5. Barriers placed at right angles to the prevailing air currents at intervals of about 10 times their height are effective in controlling soil blowing.8 .2.4. This latter condition requires prior approval from the appropriate authority. 6 12/03 3.4. Stone . Standard and Specifications for Permanent Vegetative Stabilization.8 . 3.3.4. Topsoiling .2 . Standard and Specifications for Topsoiling.4.See Section 3.3. Vegetation .Surface can be protected with crushed stone or coarse gravel.1.See Section 3. 2.Types of Permanent Methods: 1. Type of Emulsion Water Dilution Type of Nozzle Apply Gal/Ac. at right angles to the prevailing air currents at intervals of approx. scarify the soil surface to prevent or reduce the amount of blowing dust until a more appropriate solution can be implemented.Apply as flakes or granular material with a spreader at a rate that will keep the soil surface moist.Place barriers such as soild board fences.5. Detail and Specifications for Vegetative Stabilization.Apply layer of crushed stone or coarse gravel to protect soil surface. 6. Adhesives . hay bales. 7. Barriers . The following table may be used for general guidance.5:1 Coarse spray 350 4.5:1 Fine spray 235 Resin-in-water emulsion 4. Source: Adapted from VA ESC Handbook Symbol: Detail No. Std. 3. 10X their height. Latex emulsion 12. Std.4. snow fences. 2. Repeat as needed. etc.Use on mineral soils only (not effective on muck soils).3. Re-apply as necessary.Standard Detail & Specifications Dust Control Temporary Methods: 1.Sprinkle site with water until the surface is moist . Begin the tillage operation on the windward side of the site using a chisel-type plow for best results.For emergency temporary treatment. DE-ESC-3.4.4.See DE-ESC-3.4. Tillage . Vegetative cover .See DE-ESC-3. Calcium Chloride . Sprinkling .8 Sheet 1 of 1 12/03 Date: _________________ .See DE-ESC-3. 2. Stone .1 Fine spray 300 Acrylic emulsion (non-trafffic) 7:1 Coarse spray 450 Acrylic emulsion (traffic) 3.3. Standard Detail and Specifications for Mulching. Permanent Methods: 1. 5. Mulches . Keep traffic off these areas. Detail and Specifications for Vegetative Stabilization. Vegetative cover . Standard Detail & Specifications Dust Control This page left intentionally blank. 12/03 Date: _________________ . Source: Symbol: Detail No. The centerline of both roadway approaches shall coincide with the crossing alignment centerline for a minimum distance of 50 feet from each bank of the waterway being crossed. The three types of standard temporary access waterway crossings are bridges.5. c. Temporary access waterway crossings are necessary to prevent construction equipment from damaging the waterway. construction. These standard and specifications provide designs based on waterway geometry rather than the drainage area contributing to the pointof crossing. b. culverts. shall not cause a significant water level difference between the upstream and downstream water surface elevations.Of the three basic methods presented in Part 2. pollution free access across a waterway for construction equipment by establishing minimum standards and specifications for the design. and tracking sediment and other pollutants into the waterway. They should be planned to be in service for the shortest practical period of time and removed as soon as their function is completed. 1. bridges pose the least potential for creating barriers to aquatic migration.In-Stream excavation shall be limited to only that necessary to allow installation of the standard methods as presented in Part II. Elimination of Fish Migration Barriers . blocking fish migration.1 . maintenance. and removal of the structure. crossing may vary 15O from a line drawnperpendicular to the centerline of the stream at the intended crossing location. Conditions Where Practice Applies The following standard and specifications for temporary access waterway crossings are applicable in both tidal and non-tidal waterways. d. This standard and specification may represent a channel constriction thus the temporary nature of waterway access crossings must be stressed. General Requirements a. Temporary access crossings shall not be utilized to maintain traffic for the general public. In-Stream Excavation .1 12/03 . Crossing Alignment . Where approach conditions dictate. Road Approaches . The construction of any specific crossing method as presented in Part 2. The principal consideration for development of the standard and specifications is concern for erosion and sediment control. Purpose: The purpose of the temporary access waterway crossing is to provide safe.The temporary waterway crossing shall be at right angles to the stream.If physical or 6 3. and fords.STANDARD AND SPECIFICATIONS FOR TEMPORARY CROSSINGS Definition: A temporary crossing is a structure placed across a waterway to provide access for construction purposes for a period of less than one year. Structural utility and safety must also be considered when designing temporary access waterway crossings to withstand expected loads. as appropriate. f. Larger aggregates will be allowed. Site Location . Maintenance of crossing . Time of Operation . Materials i. When possible locate the crossing at a point receiving minimal surface runoff. f. Considerations for Choosing a Specific Method The following criteria for erosion and sediment control shall be considered when selecting a specific temporary access waterway crossing standard method: a.Locate the temporary crossing where there will be the least disturbance to the soils of the existing waterway banks. The bridge method should require the least maintenance where as the ford method will probably require more intensive maintenance.Vehicular loads.Geotextile is a fabric consisting of either woven or nonwoven plastic.Ease of removal and subsequent damage to the waterway should be primary factors in considering the choice of a standard method. If the roadway approach is constructed with a reverse grade away from the waterway.The physical constraints of a site may preclude the selection of one or more of the standard methods. a separate diverting structure is not required. Consider the effort that will be required to restore the area after the temporary crossing is removed. e. All fill materials associated with the roadway approach shall be limited to a maximum height of 2 feet above the existing floodplain elevation. Road Width . g. Unless prior written approval is obtained from the Delaware Department of Natural Resources and Environmental Control. allow increased drainage of the aggregate and reduce mixing of the aggregate with the subgrade soil. ii.5. This will prevent roadway surface runoff from directly entering the waterway. traffic patterns. all structures shall be removed within one year from the date of the installation.A water diverting structure such as a swale shall be constructed (across the roadway on both roadway approaches) 50 feet (maximum) on either side of the waterway crossing. Site aesthetics . and frequency of crossings should be considered in choosing a specific method. d.There shall be no earth or soil materials used for construction within the waterway channel. Aggregate . g.All crossings shall have one traffic lane.right-of-way restraints preclude the 50 feet minimum. b. Design criteria for this diverting structure shall be in accordance with the “Standard and Specifications” for the individual design standard of choice. Geotextile . polypropylene.The time of year may preclude the selection of one or more of the standard methods due to fish spawning or migration restrictions.All temporary crossings shall be removed within 14 calendar days after the structure is no longer needed. Time of Year . Geotextiles shall be Type GS-I in accordance with the specifications contained in Appendix A-3.Select a standard design method that will least disrupt the existing terrain of the stream reach. 6 12/03 3.2 . The minimum width shall be 12 feet with a maximum width of 20 feet. Vehicular loads and traffic patterns . The 50 feet is measured from the top of the waterway bank. e. or nylon used to distribute the load. a shorter distance may be provided. 2. DE #3 stone shall be the minimum acceptable aggregate size for temporary crossings. retain fines.The standard methods will require various amounts of maintenance. Removal of the structure . or the local conservation district. c.1 . Physical site constraints . Surface Water Diverting Structure . h. since disturbance to the waterway is only during construction and removal of the culvert. anticipated loading may prove unsafe for single span bridges. corrugated metal. If a channel width exceeds 3 feet. This temporary waterway crossing method is normally preferred over a ford type of crossing. 2. Considerations 1.5. the channel is too wide for normal bridge construction. 3. Culvert Size The size of the culvert pipe shall be the largest pipe diameter that will fit into the existing channel without major excavation of the waterway channel or without major approach fills. Culvert Strength All culverts shall be strong enough to support their cross sectional area under maximum expected loads. pipe arches. or oval pipe of reinforced concrete. or c. The minimum size culvert that may be used is a 12" diameter pipe.5 12/03 . Temporary culverts can be salvaged and reused. which is used to convey flowing water through the crossing.ADDITIONAL STANDARD AND SPECIFICATIONS FOR TEMPORARY CULVERT CROSSING Definition: A temporary access culvert is a structure consisting of a section(s) of circular pipe. or structural plate. additional pipes may be used until the cross sectional area of the pipes is greater than the percent of the cross sectional area of the existing channel. b. access is not needed from bank to bank.1 . 6 3. Temporary culverts are used where: a. 6 . 6 12/03 3.1 .This page left intentionally blank.5. 1 Sheet 1 of 2 12/03 Date: _________________ .1. of pipe or 12".) Source: Adapted from VA ESC Handbook Typical Section Symbol: Detail No.Standard Detail & Specifications Temporary Crossing . Top of bank Top of bank Stream Channel Diversion and/or swale Diversion and/or swale Plan DE #3 stone 1/2 dia. TC-C DE-ESC-3.Culvert Flow Riprap base DE #3 stone 50' min. 50' min.5. whichever is greater 6" deep Total capacity of pipe culverts = flow Riprap base Type GS-1 geotextile fabric DATA Pipe diameter (D) Number of pipes (No.) Pipe material & thickness Riprap size (R No. d. TC-C DE-ESC-3. restoration of original stream channel cross section. and that sediment is not entering the stream or blocking fish passage or migration. If multiple culverts are used they shall be separated by at least 12" of compacted aggregate fill. b. Stabilization . This shall include removal and disposal of any trapped sediment or debris. Removal . Culvert Length .Periodic inspection shall be performed to ensure that the culverts. 4. and protection of the streambanks from erosion. Final Clean-up . removal of all construction materials.The culvert(s) shall be covered with a minimum of one foot of riprap with a 6 inch top layer of coarse aggregate. Restrictions .When the crossing has served its purpose.Maintenance shall be performed as needed.All areas disturbed during culvert removal shall be stabilized within 14 calendar days in accordance with the Standard and Specifications for Permanent Vegetative Stabilization.No construction or removal of a temporary access culvert will be permitted from March 15 through June 15 to minimize interference with fish spawning and migration. Geotextile .Culvert Construction Notes: 1.Standard Detail & Specifications Temporary Crossing . the culvert materials shall be removed within one year of installation. d. and streambanks are not damaged. Source: Adapted from VA ESC Handbook Symbol: Detail No. Removed materials shall be stored outside of the waterway floodplain.Removal of the structure and clean up of the area shall be accomplished without construction equipment working in the waterway channel. 3. Sediment shall be disposed of and stabilized outside the waterway floodplain. Geotextile fabric reduces settlement and improves crossing stability. Inspection .All areas disturbed during culvert installation shall be stabilized within 14 calendar days in accordance with the Standard and Specifications for Temporary Vegetative Stabilization.1. In no case shall be culvert exceed 40 feet length.5.1 Sheet 2 of 2 12/03 Date: _________________ . Culvert Placement .The culvert(s) shall extend a minimum of one foot beyond the upstream and downstream toe of the aggregate placed around the culvert.Type GS-1 geotextile shall be placed so as to cover the streambed and extend minimum six inches and a maximum one foot beyond the end of the culvert prior to installing the bedding material. Restoration a. Method . Further restrictions may apply in accordance with other State and/or Federal permits. bedding and filter cloth materials shall be removed within 14 calendar days. c. In all cases. e. Culvert Protection . 2. in a timely manner to ensure that structures are in compliance with this standard and specification. b. Maintenance a.Final clean-up shall consist of removal of the temporary structure from the waterway. b. c. Installation a. Maintenance . all structures including culverts. Final Stabilization . stream bed.The invert elevation of at least 1 (one) culvert shall be installed 1 (one) foot below the natural streambed grade to minimize interference with fish migration. 7 12/03 .5. Therefore. However. Considerations Temporary timber mats are typically used where the streambanks are less than a few feet above the invert of the stream. 6 3. the use of timber mats may be approved for higher stream banks if adequate approaches can be provided. timber mats are generally preferred over other temporary crossings which require the placing of stone in the streambed.1 . Design Criteria The timbers used for temporary mat crossings shall be of adequate size to support the equipment intended to cross it.ADDITIONAL STANDARD AND SPECIFICATIONS FOR TEMPORARY TIMBER MAT CROSSING Definition: A temporary timber mat is a shallow structure placed in the bottom of a waterway over which water flows while still allowing traffic to cross the waterway. Rods or cable links must be adequate to remain serviceable during continuous use and to resist breaking during handling. 6 12/03 3.8 .This page left intentionally blank.1 .5. 5.) Profile Source: Delaware ESC Handbook Symbol: Detail No.1.Standard Detail & Specifications Temp.2 Sheet 1 of 2 12/03 Date: _________________ . Crossing .Timber Mat Plan Timber planking (typ. TC-M DE-ESC-3. and that sediment is not entering the stream or blocking fish passage or migration. 4.Maintenance shall be performed as needed. 2. Crossing . Stabilization .2 Sheet 2 of 2 12/03 Date: _________________ . Final Clean-up . Method . 3. Removal . c. all components shall be removed within 14 calendar days.5.Final clean-up shall consist of removal of the temporary structure from the waterway.Removal of the structure and clean up of the area shall be accomplished without construction equipment working in the waterway channel.Standard Detail & Specifications Temp.No installation or removal of a temporary timber mat crossing will be permitted from March 15 through June 15 to minimize interference with fish spawning and migration. d. Restrictions . and streambanks are not damaged. and protection of the streambanks from erosion. removal of all construction materials.All areas disturbed during the installation shall be stabilized within 14 calendar days of the disturbance in accordance with the Standard and Specifications for Temporary Vegetative Stabilization.Periodic inspection shall be performed to ensure that the crossing. Inspection . In all cases. When the crossing has served its purpose.All areas disturbed during culvert removal shall be stabilized within 14 calendar days of the disturbance in accordance with the Standard and Specifications for Permanent Vegetative Stabilization. Further restrictions may apply in accordance with other State and/or Federal permits. This shall include removal and disposal of any trapped sediment or debris. in a timely manner to ensure that structures are in compliance with this standard and specification.1. Final Stabilization . TC-M DE-ESC-3. b. b. stream bed. Sediment shall be disposed of and stabilized outside the waterway floodplain. Source: Delaware ESC Handbook Symbol: Detail No. Installation a.Mats shall be placed only in those areas designated on the approved plan. restoration of original stream channel cross-section.Timber Mat Construction Notes: 1. Placement .It may be necessary to temporarily remove a timber mat crossing in anticipation of unusual storm events. Maintenance . Removed materials shall be stored outside of the waterway floodplain. b. the crossing materials shall be removed within one year of installation. Restoration a. Maintenance a. 1 . Temporary access bridges pose the least chance for interference with fish migration when compared to the other temporary access waterway crossings. Design Criteria 1. Considerations 1. 6 3. metal.Decking materials shall be of sufficient strength to support the anticipated load. 2. Temporary access bridges are the preferred structures for providing temporary waterway crossings. 2. Decking materials . or other materials which provides access across and stream or waterway. or other approved materials.ADDITIONAL STANDARD AND SPECIFICATIONS FOR TEMPORARY BRIDGE CROSSING Definition: A temporary access bridge is a structure made of wood. 3. prestressed concrete beams.9 12/03 . metal beams. bridge construction causes the least disturbance to the waterway bed and banks when compared to the other access waterway crossings. Stringers . Normally.5.Stringers shall either be logs. Most bridges can be quickly removed and reused. sawn timber. 1 .10 .5. 6 12/03 3.This page left intentionally blank. 50' t o diversio n Anchor w/safety chain or cable Perspectiv erspectivee DATA Stringer material Stringer dimensions Decking material Decking dimensions Source: Adapted from MD Stds. for ESC Symbol: Detail No.Bridge DE #3 stone on geotextile fabric Min. TC-B DE-ESC-3.3 Sheet 1 of 3 12/03 Date: _________________ .5.1. & Specs.Standard Detail & Specifications Temporary Crossing . f. for ESC Symbol: Detail No. Bridge Span . Curbs or fenders .Bridges shall be constructed to span the entire channel. they may be necessary to properly distribute loads. b. Restrictions .No construction or removal of a temporary access bridge will be permitted from March 15 through June 15 to minimize interference with fish spawning and migration. If the channel width exceeds 8 feet (as measured from top-of-bank to top-of-bank) then a footing. TC-B DE-ESC-3.Bridges shall be securely anchored at only one end using steel cable or chain. Deck Material . c. Stabilization .All decking members shall be placed perpendicular to the stringers.Standard Detail & Specifications Temporary Crossing .3 Sheet 2 of 3 12/03 Date: _________________ . Bridge Anchors . Installation a. Anchoring shall be sufficient to prevent the bridge from floating down stream and possibly causing an obstruction to the flow. Decking materials must be butted tightly to prevent any soil material tracked onto the bridge from falling into the waterway below. Abutments . One run plank shall be provided for each track of the equipment wheels. and securely fastened to the stringers. Further restrictions may apply in accordance with other State and/or Federal permits. large boulders. pier or bridge support will be permitted for each additional 8 foot width of the channel.A temporary bridge structure shall be constructed at or above bank elevation to prevent the entrapment of floating materials and debris. no footing. h.All areas disturbed during bridge installation shall be stabilized within 14 calendar days of the disturbance in accordance with the Standard and Specifications for Temporary Vegetative Stabilization. & Specs. or driven steel anchors.Run planking shall be securely fastened to the length of the span. pier or bridge support will be permitted within the channel for waterways less than 8 feet wide. Acceptable anchors are large trees. Curbs or fenders are an option which will provide additional safety.1. d.Abutments shall be placed parallel to and on stable banks.Bridge Construction Notes: 1.5. butted tightly. g. However. Run Planks (optional) . One additional footing. Although run planks are optional. e.Curbs or fenders may be installed along the outer sides of the deck. Bridge Placement . 2. pier or bridge support may be constructed within the waterway. Anchoring at only one end will prevent channel obstruction in the event that floodwaters float the bridge. Source: Adapted from MD Stds. Final clean-up shall consist of removal of the temporary structure from the waterway.Standard Detail & Specifications Temporary Crossing . c. and that sediment is not entering the stream or blocking fish passage or migration. Final Stabilization . 4. d. Final Clean-up . Method . b. Restoration a. Sediment shall be disposed of and stabilized outside the waterway floodplain. Inspection .1. b. Removed materials shall be stored outside of the waterway floodplain.Bridge Construction Notes (cont.) 3.Maintenance shall be performed as needed.3 Sheet 3 of 3 12/03 Date: _________________ . Maintenance .Periodic inspection shall be performed to ensure that the structure. the structure shall be removed within one year of installation. In all cases.All areas disturbed during removal shall be stabilized within 14 calendar days of the disturbance in accordance with the Standard and Specifications for Permanent Vegetative Stabilization. removal of all construction materials. in a timely manner to ensure that structures are in compliance with this standard and specification. all structures including bedding and filter cloth materials shall be removed within 14 calendar days. restoration of original stream channel cross section.5. This shall include removal and disposal of any trapped sediment or debris. Source: Adapted from MD Stds. streambed. & Specs. for ESC Symbol: Detail No.When the crossing has served its purpose. and streambanks are not damaged.Removal of the structure and clean up of the area shall be accomplished without construction equipment working in the waterway channel. Maintenance a. TC-B DE-ESC-3. and protection of the streambanks from erosion. Removal . Bridge This page left intentionally blank. Source: Symbol: Detail No. 12/03 Date: _________________ .Standard Detail & Specifications Temporary Crossing . This would typically be based on the 2-year return period event. Design Criteria 1. This can be accomplished through the use of temporary earth dikes and/or swales in accordance with the appropriate Design Standards and Specifications.5.Provisions shall be made to direct surface flow away from the ford and its approaches. and the streambed is armored with naturally occurring bedrock. Considerations Temporary fords may be used where the streambanks are less than 4 feet above the invert of the stream. 6 3.1 .ADDITIONAL STANDARD AND SPECIFICATIONS FOR TEMPORARY FORD CROSSING Definition: A temporary ford is a shallow structure placed in the bottom of a waterway over which water flows while still allowing traffic to cross the waterway. However.11 12/03 . or can be protected with an aggregate layer in accordance with these specifications.The stone used for temporary fords shall be of adequate size and weight to resist anticipated storm flows. for work near certain highly sensitive protected areas. design storms of greater magnitude may be warranted. Stone . Surface flow . 2. 1 .This page left intentionally blank.5. 6 12/03 3.12 . Stone Ford 4' Max. TC-F DE-ESC-3. & Specs. Bank Height 5:1 or Surface flow diverted by temporary earth dike and/or swale. Crossing .Standard Detail & Specifications Temp. for ESC Symbol: Detail No.1.5.4 Sheet 1 of 3 12/03 Date: _________________ . flat ter DE #3 stone and/or riprap on Type GS-I geotextile fabric Perspectiv erspectivee DATA Median stone size (d50) Source: Adapted from MD Stds. for ESC Symbol: Detail No. streambanks and the road approaches prior to placing the bedding material on the streambed or approaches. & Specs. Source: Adapted from MD Stds. Further restrictions may apply in accordance with other State and/or Federal permits. c. in no case will the bedding material be placed deeper than 12 inches or one-half (1/2) the height of the existing banks. g.No construction or removal of a temporary access ford will be permitted from March 15 through June 15 to minimize interference with fish spawning and migration. The approaches. Stone used in ford construction shall meet the minimum requirements of the Del-DOT. 2.1. If needed. Spoil material from the banks shall be stored out of the floodplain and stabilized. as needed. temporary dikes and/or swales shall be constructed in accordance with the appropriate Standard Detail and Specifications to divert surface flow away from the ford and its approaches.5. The filter cloth shall extend a minimum of 6 inches and a maximum 1 foot beyond bedding material. The approach roads at the cut banks shall be no steeper than 5:1. The entire ford approach (where banks were cut) shall be covered with filter cloth and have four (4) inches of aggregate placed on top of the filter cloth. and ford shall be constructed of DE #3 stone as a minimum. whichever is smaller.4 Sheet 2 of 3 12/03 Date: _________________ . However. Restrictions . e. where higher flows are anticipated. Crossing . d. b. Larger riprap may be placed as a surface layer. bedding. f.Stone Ford Construction Notes: 1. The placing of any material in the waterway bed will cause some upstream ponding. One layer of Type GS-I geotextile fabric shall be placed on the streambed. TC-F DE-ESC-3.Standard Detail & Specifications Temp. Installation a. The depth of this ponding will be equivalent to the depth of the material placed within the stream and therefore should be kept to a minimum height. Fords shall not be installed when the streambanks are 4 feet or more in height above the invert of the stream. All fords shall be constructed to minimize the blockage of stream flow and shallow flow over the ford. h. Maintenance . TC-F DE-ESC-3. Sediment shall be disposed of and stabilized outside the waterway floodplain.Final clean-up shall consist of removal of excess temporary ford materials from the waterway. excess material used for this structure need not be removed. e.When the temporary structure has served its purpose. in a timely manner to ensure that structures are in compliance with this standard and specification. Source: Adapted from MD Stds.5. b. All materials shall be stored outside the waterway floodplain.) i. d. Approach Disposition . and streambanks are not damaged. for ESC Symbol: Detail No. Final Clean-up .All areas disturbed during ford removal shall be stabilized within 14 calendar days of that disturbance in accordance with the Standard and Specifications for Permanent Vegetative Stabilization. and that sediment is not entering the stream or blocking fish passage or migration.Stone Ford Construction Notes (cont. Crossing . 3. c. Inspection .Clean up shall be accomplished without construction equipment working in the stream channel.4 Sheet 3 of 3 12/03 Date: _________________ .Maintenance shall be performed as needed. Restoration a. b.The approach slopes of the cut banks shall not be backfilled. streambed. Method . This shall include removal and disposal of any trapped sediment or debris. Care should be taken so that any aggregate left does not create an impoundment or impede fish passage. 4.Periodic inspection shall be performed to ensure that the ford. All areas disturbed during ford installation shall be stabilized within 14 calendar days of the disturbance in accordance with the Standard and Specifications for Temporary Vegetative Stabilization. Final Stabilization . Maintenance a. & Specs. Removal .Standard Detail & Specifications Temp.1. Stone Ford This page left intentionally blank. Crossing .Standard Detail & Specifications Temp. Source: Symbol: Detail No. 12/03 Date: _________________ . It is often a difficult task to decide what type of control to use under such circumstances. Structures or methodology for crossing streams with larger drainage areas require project specific plans which are designed using methods which more accurately define the actual hydrologic and hydraulic parameters which will affect the functioning of the structure. The designer and plan reviewer should also be aware that such modifications are subject to other state and federal construction permits. Conditions Where Practice Applies: Generally applicable to flowing streams with drainage areas less than one square mile. Some practices. There is some flexibility in the implementation of these controls. in some cases it may be more environmentally beneficial to provide substantial controls for the approach areas rather than install extensive measures in the stream itself which would extend the exposure time of the disturbance. designers and plan reviewers should always make site visits of the proposed area to ensure that the most appropriate method is chosen. Purpose: To prevent sediment from entering a water body due to construction within approach areas and to minimize the amount of disturbance within the stream itself. consideration must be given to providing adequate mitigation of sediment loss while minimizing the amount of encroachment and time spent working in the channel. A method such as "boring and jacking" of utilities below a streambed. consideration should be given to substantial in-stream controls or use of a stream diversion in order to prevent excessive sedimentation damage. when construction activities within streambed and banks will take an extended period of time. by virtue of its very nature. 6 3. Because of the difficulty in choosing the right method for in-stream activities. which would prevent disturbance within the watercourse. For example. in cases where in-stream work is unavoidable. occasionally crosses and impacts free-flowing streams.2 . Planning Considerations: Construction activity.STANDARD AND SPECIFICATIONS FOR STREAM DIVERSION Definition: A strategy for controlling construction activities in or adjacent to streams. There is a potential for excessive sediment loss into a stream by both the disturbance of the approach areas and by the work within the stream-bed and banks. might also be applicable to construction activities in or adjacent to larger bodies of water such as ponds or lakes under certain circumstances. such as cofferdams. However.5. is the preferred method whenever practical. However.1 12/03 . Temporary diversion channels shall be stabilized with a lining capable of withstanding expected erosive forces.Design Criteria: Stream diversions under this standard and specification shall be designed in accordance with the following guidelines: 1. as follows: a. Riprap or sandbag: 9. c. 1 day: Existing flow of the watercourse. The following linings are acceptable for the max.p. All materials used in the construction of the stream diversion (i. stone. velocities indicated: a.. This will ensure the work area remains dry and that no construction materials float downstream.p.9.0 f. etc. b. The design flow shall be determined based on the expected construction time.2. Temporary diversion pipes shall be limited to use in situations where they will remain in place no more than 14 days.2 .p.s.e.2 . 2. Maintenance: Care must be taken to inspect any stream diversion at the end of each day to make sure that the construction materials are positioned securely.) must generally conform to the Standards and Specifications for Temporary Crossings. Geotextile fabric: 2. 2 . The pipe should be large enough to convey the design flow without appreciably altering the stream flow characteristics.5 f. pipe. The drainage area should be no greater than one (1) square mile (640 acres).s. construction materials which could become floatable debris should be moved to higher ground.5 . Polyethylene or vegetation: 0 . b. Surface water diverting structures should be used at all trenching and/or construction road approaches within 50 feet on either side of the crossing. 4.5. 6. 5.14 days: 2-year frequency storm. geotextile fabric. 6 12/03 3.0 . 3. Stream diversions shall be designed so as not to alter the flow either upstream or downstream from the work area. If a runoff event is anticipated.s.13.0 f. 1 Sheet 1 of 3 12/03 Date: _________________ .Standard Detail & Specifications Utility Crossing Diversion Pipe Proposed utility B Existing stream bank Diversion Pipe Plug Plug Flow Additional controls for approach areas (as specified) Excavated trench B Additional controls for approach areas (as specified) A A DATA Plan Diversion pipe diameter (D) Plug material Impermeable material Dewatering practice Source: Adapted from VA ESC Handbook Symbol: Detail No. DP DE-ESC-3.2.5. 1 Sheet 2 of 3 12/03 Date: _________________ . Upstream plug shall be made waterproof using Type GS-I geotextile or other means.Standard Detail & Specifications Utility Crossing Diversion Pipe Existing streambank Plug* Diversion pipe Flow Streambed Proposed utility Excavated trench Section A-A Existing streambank Plug* Water level Diversion pipe Proposed utility Section B-B *NOTE: Plug shall consist of coarse aggregate. DP DE-ESC-3.2. rirap. as specified. sandbags or other material capable of resisting expected flows.5. Source: Adapted from VA ESC Handbook Symbol: Detail No. Once the utility has been installed.5. in-stream construction periods shall be less than 72 hours. 4. All materials used must be adequate to withstand expected hydraulic and equipment loads. 5. 8. 6.Standard Detail & Specifications Utility Crossing Diversion Pipe Construction Notes: 1.2. Diversion pipe shall remain in-place until stream bed and banks have been stabilized.1 Sheet 3 of 3 12/03 Date: _________________ . Pipe shall be of adequate size to convey the normal water channel flow and shall be installed in the stream bed across the proposed utility trench centerline. Pipe diversion shall be operational prior to start of in-stream construction. This practice limited to streams less than 10' wide. Installation of the utility shall proceed in a timely manner so as to minimize in-stream construction. Controls for approach areas shall be provided in accordance with the approved plan. excavation of the utility trench may begin. 3. Impervious plug shall be placed near each end ot pipe so as to dam off the channel flow and force it into the diversion pipe. trench shall be backfilled and stabilized in accordance with the approved plan. 7. Source: Adapted from VA ESC Handbook Symbol: Detail No. Water trapped between the plugs shall be pumped to an approved dewatering practice prior to excavation of the utility trench. Once the diversion pipe has been made operational and checked for water tightness. 9. 2. DP DE-ESC-3. Standard Detail & Specifications Utility Crossing Diversion Pipe This page left intentionally blank. 12/03 Date: _________________ . Source: Symbol: Detail No. separate cofferdams shall be constructed from each bank.5. CD DE-ESC-3.O. etc.2.Standard Detail & Specifications Cofferdam Stream Diversion Existing stream width (W) WE = 1/2 W (Min. riprap.) for full stream crossings WE Sandbags. WB = 1/4 W (Min. A WB Excavation L.) A Flow Type GS-I geotextile Dewatering facility NOTE: For full stream crossings.2 Sheet 1 of 2 12/03 Date: _________________ . Plan W Perimeter controls Type GS-I geotextile Perimeter controls WE DATA Width of excavation (WE) By-pass flow width (WB) Cofferdam material & size Impermeable material Dewatering practice Source: Adapted from VA ESC Handbook Excavation Section A-A Symbol: Detail No.D. Cofferdam shall be formed by placing riprap. 2. sandbags.Standard Detail & Specifications Cofferdam Stream Diversion Construction Notes: 1. Repeat the operation from the opposite bank. Once adequately dewatered. 6. woody vegetation.5. Source: Adapted from VA ESC Handbook Symbol: Detail No. as required. or other material in the streambed and banks which may preclude proper installation of the cofferdam materials and/or impede the proposed construction shall be removed. Water in the work area shall be pumped to an approved dewatering practice. 3. If a full stream crossing is required. 8.2. Height of the cofferdam shall be adequate to keep water from overtopping the dam and flooding the work area. in-stream construction may begin from the first bank and proceed to the centerline of the stream. 5. all disturbed areas within the first work area shall be stabilized in accordance with the approved plan prior to dismantling and reconstructing the cofferdam on the opposite bank. 4. sheet metal or wood planks in a semicircle around the proposed work area. 9. Large rocks. 7. Controls for approach areas shall be provided in accordance with the approved plan. Construction shall be performed during low flow conditions. Cofferdam shall not impede the flow of the stream in any way.2 Sheet 2 of 2 12/03 Date: _________________ . CD DE-ESC-3. 5. sandbags. etc. See separate detail. sheet piling.) Place riprap at transition Perspectiv erspectivee Source: Adapted from VA ESC Handbook Symbol: Detail No.Standard Detail & Specifications Stream Diversion Channel Silt fence ( Temporary crossing Typical. SD DE-ESC-3. Flo w ) A Place riprap at transition Flo w Flow barrier Original streambed A Flow barrier (riprap. jersey barriers.2. as needed.3 Sheet 1 of 3 12/03 Date: _________________ . or width of exist.2.Standard Detail & Specifications Stream Diversion Channel Silt fence (typ.) Polyethylene (6 mil.) or Type GS-I geotextile liner Existing ground Entrench silt fence and liner in same trench B Section A-A (Low vvelocity elocity lining) NOTE: Channel bottom width (B) to be 6' min.5. SD DE-ESC-3.3 Sheet 2 of 3 12/03 Date: _________________ .) Filter fabric Riprap or sandbag liner Existing ground Entrench silt fence and filter fabric in same trench B Section A-A (High vvelocity elocity lining) DATA Channel bottom width (B) Lining specification Source: Adapted from VA ESC Handbook Symbol: Detail No. stream. which ever is less. Silt fence (typ. min. wooden stakes shall not be used for this purpose.5. Liners shall be secured at the upstream and downstream ends with riprap or other non-erodible material which will allow normal flow of the stream. Water in the construction area shall be pumped to an approved dewatering practice. 9.2. 5. Maximum steepness of sideslopes shall be 2:1. if used. The upstream flow barrier shall then be removed and the material placed in the upstream end of the diversion. the downstream flow barrier in the original stream shall be removed first. This material shall not have soil mixed in. SD DE-ESC-3. Once in-stream construction has been completed and all disturbed areas stabilized. wood planking. 3. as needed. Source: Adapted from VA ESC Handbook Symbol: Detail No. shall be buried or removed and properly disposed of in accordance with the job specifications. whichever is less. Stream flow shall be diverted away from the work area in the original streambed using nonerodible. Minimum width of bottom shall be 6' or equal to the bottom width of the existing streambed. thus redirecting flow back to the original stream channel. but shall be sufficient to ensure continuous flow of water in the diversion. Additional material may be placed along the length of the diversion. depending on site conditions. of 18". 11. These materials shall be placed so as to prevent or reduce water backing up into the construction area. jersey barriers. sand bags. etc. Liners shall be secured to the side slopes of the diversion channel using staples and patterns similar to those used for erosion control matting. 12. Depth and grade may be variable. 7. Once the diversion has been sealed at both ends. 8. Diversion channel shall be operational prior to any in-stream construction. to secure the liner.3 Sheet 3 of 3 12/03 Date: _________________ . sheet pile. 4. backfilling of the diversion channel may begin. impervious materials such as riprap with geotextile. upstream sections shall overlap downstream sections by a min. All disturbed areas shall be stabilized in accordance with the approved plan. 10. Liner shall be entrenched at the top of the slope or slope break as shown in the detail. Liner material. 6. Channel lining shall be as specified and installed in accordance with the appropriate detail. 2. If a single or continuous liner is not available or is impractical.Standard Detail & Specifications Stream Diversion Channel Construction Notes: 1. Silt fence or other perimeter control shall be provided unless the liner is extended far enough to prevent sediment from reaching the stream. The diversion shall then be sealed at the downstream end. Source: Symbol: Detail No.Standard Detail & Specifications Stream Diversion Channel This page left intentionally blank. 12/03 Date: _________________ . whether it be flowing channel. a qualified engineer and product manufacturer should be consulted. turbidity curtains should not be installed across channel flows.STANDARD AND SPECIFICATIONS FOR TURBIDITY CURTAIN Definition: A floating geotextile material which minimizes sediment transport from a disturbed area adjacent to. Conditions Where Practice Applies: Applicable to non-tidal and tidal watercources where intrusion into the watercourse by construction activities and subsequent sediment movement is unavoidable. In most situations. pond. In time. Purpose: To provide sedimentation protection for a watercourse from up-slope land disturbance or from dredging or filling within the watercourse. For situations where there are greater flow velocities or currents. The specifications contained within this practice pertain to minimal and moderate flow conditions where the velocity of flow may reach 5 feet per second (or a current of approx.1 12/03 . A turbidity curtain is designed to deflect and contain sediment within a limited area and provide enough residence time so that soil particles will fall out of suspension and not travel to other areas. Turbidity curtains are not designed to act as water impoundment dams and can not be expected to stop the flow of a significant volume of water. 3 knots).3 . Planning Considerations: Soil loss into a watercourse results in long-term suspension of sediment. or within a body of water. the volume of water contained within the curtain will be much greater at high tide versus low tide and measures must be taken to prevent the curtain from submerging. In tidal or moving water conditions. provisions must be made to allow the volume of water contained within the curtain to change. lake. In addition to allowing for slack in the curtain to rise and fall. Turbidity curtain types must be selected based on the flow conditions within the water body . the suspended sediment may travel large distances and affect wide-spread areas. water must be allowed to flow through the curtain if the curtain is to remain in roughly the same spot and to maintain the 6 3. not to halt the movement of the water itself. or a tidal watercourse.5. They are designed and installed to trap sediment. Consideration must also be given to the direction of water movement in channel flow situations. Since the bottom of the curtain is weighted and external anchors are frequently added. Design Criteria: 1. 3.3 . Regardless of the decision made. 6. In addition. make installing easier and reduce stress from potential wave action during high winds. this is achieved by constructing part of the curtain from a heavy woven geotextile fabric. the use of the turbidity curtain during land disturbance is essential. 4.5 feet per second) and/or wind and wave action can affect the curtain. the curtain should never be so long as to touch the bottom. soil particles should always be allowed to settle for a minimum of 6-12 hours prior to their removal by equipment or prior to removal of the curtain. This will allow for measuring errors. but retains the sediment pollutants. 6 12/03 3. even in deep water. The fabric allows the water to pass through the curtain. allow an additional 10-20% variance in the straight line measurements. 7. The Type 3 configuration should be used in areas where considerable current (up to 3 knots or 5 feet per second) may be present and/or where the curtain is potentially subject to wind and wave action. 2. Tubididty curtains should not be placed across the main flow of a significant body of moving water. It is therefore recommended that the soil particles trapped by a turbidity curtain only be removed if there has been a significant change in the original contours of the affected area in the watercourse. However. it is seldom practical to extend a turbidity curtain depth lower than 10 to 12 feet below the surface. The principal strategy for a project involving disturbances along or within a water body should be to keep sediment out of the watercourse. which will result in an effective depth which is significantly less than the skirt depth. The Type 2 configuration should be used in areas where there may be small to moderate current running (up to 2 knots or 3. consideration must be given to the probable outcome of the procedure. Consideration should be given to the volume of water that must pass through the fabric and sediment particle size when specifying fabric permeability. 5. Normally.2 . The Type 1 configuration should be used in protected areas where there is no current and the area is sheltered from wind and waves.5. when proximity to the watercourse makes successfully mitigating sediment loss impossible. Sediment which has been deflected and settled out by the curtain may be removed if so directed by the on-site inspector or the plan approval agency. Movement of the lower skirt over the bottom due to tidal reverses or wind and wave action on the flotation system may fan and stir sediments already settled out. A minimum 1-foot gap should exist between the weighted lower end of the skirt and the bottom at mean low water. 8. It is possible that the resuspension of particles and/or the accidental dumping of the material could create a more serious problem than leaving it in place. a curtain installed in such a manner can "billow up" towards the surface under the pressure of the moving water. Turbidity curtains should be located parallel to the direction of flow of a moving body of water. Curtains which are installed deeper than this will be subject to very large loads with subsequent strain on curtain materials and the mooring system.same shape. When sizing the length of the floating curtain. In tidal and/or wind and wave action situations. However. Turbidity curtains should extend the entire depth of the watercourse whenver the watercourse in question is not subject to tidal action and/or significant wind and wave forces. In tidal and/or wind and wave action situations. Maintenance: 1. The manufacturer's instructions must be followed to ensure the adequacy of the repair.5. repair kits are generally available from the manufacturer.3 12/03 . the curtain and related components shall be removed in such a manner as to minimize turbidity. a minimum continuous span of 50 feet between joints is a good "rule of thumb".9. An attempt should be made to avoid an excessive amount of joints (anchor or stake locations) in the curtain. For stability reasons. a maximum span of 100 feet between joints is also a good rule to follow. Sediment may be removed and the original depth (or plan elevation) restored. 3. Should repairs to the geotextile fabric become necessary. 6 3. Remaining sediment shall be sufficiently settled before removing the curtain.3 . The individual(s) identified on the plan as responsible for maintenance of the curtain shall do so for the duration of the project in order to ensure the continuous protection of the watercourse. 2. 10. When the curtain is no longer required as determined by the inspector. Any spoils must be taken to an approved upland disposal area and stabilized in accordance with the approved plan. 6 12/03 3.5.This page left intentionally blank.3 .4 . CHAIN (BLOW-UP OF SHACKLE CONNECTION) Typical Section . from Amer.3 Sheet 1 of 8 12/03 Date: _________________ . or 3) Layout (Std. 300 LB/IN. TC-(1/2/3) (Std/Alt) DE-ESC-3.Standard Detail & Specifications Turbidity Curtain 5/8 IN. POLYPROPYLENE ROPE 1/4 IN. STANDARD DEPTH ACCORDING TO NEED NYLON REINFORCED VINYL ALL SEAMS HEAT SEALED 1/4 IN. Boom and Barrier Corp.5.2.TType ype 1 DATA Curtain type (1. Symbol: Detail No. or Alt. TIE ROPE FLOATATION FOLDS FOR COMPACT STORAGE ECONOMY FABRICS AVAILABLE 18 OZ.) Source: Adapt. 5. or 3) Layout (Std.Standard Detail & Specifications Turbidity Curtain 18 (OR 22) OZ. from Amer. CHAIN BALLAST & LOAD LINE Typical Section . VINYL COVERED NYLON GALVANIZED #24 SAFETY HOOK TOP LOAD LINE 5/16 VINYL COATED CABLE WATER SEAL PVC SLOT-CONNECTOR FLOATATION STRESS PLATE (TO REMOVE PRESSURE FROM FLOATS) 100 FT. Symbol: Detail No. or Alt. TC-(1/2/3) (Std/Alt) DE-ESC-3. 2. Boom and Barrier Corp.TType ype 2 DATA Curtain type (1.3 Sheet 2 of 8 12/03 Date: _________________ . STANDARD LENGTH FOLDS EVERY 6 FEET DEPTH ACCORDING TO NEED STRESS BAND STRESS PLATE 5/16 IN.) Source: Adapt. or Alt. NYLON REINFORCED VINYL STRESS BAND FLOATATION PVC SLOT . CHAIN Typical Section . or 3) Layout (Std.Standard Detail & Specifications Turbidity Curtain 22 OZ.3 Sheet 3 of 8 12/03 Date: _________________ . Boom and Barrier Corp. 2.) Source: Adapt. Symbol: Detail No.TType ype 3 DATA Curtain type (1.CONNECTOR DEPTH ACCORDING TO NEED 5/16 VINYL COATING CABLE (ON BOTH SIDES OF CURTAIN TO REDUCE STRAIN) #24 SAFETY HOOK STRESS PLATE LAP LINK 5/16 IN. TC-(1/2/3) (Std/Alt) DE-ESC-3. from Amer.5. TC-(1/2/3) (Std/Alt) DE-ESC-3. TURBIDITY CURTAIN * THIS DISTANCE IS VARIABLE Plan .Std.5. FILL AREA 100' TYP.3 Sheet 4 of 8 12/03 Date: _________________ . STAKE OR ANCHOR. Layout Source: Adapt.Standard Detail & Specifications Turbidity Curtain NOTE: The standard layout shown is intended for use in streams. Boom and Barrier Corp. Symbol: Detail No. EVERY 100' (TYPICAL) SHORELINE LIMITS OF CONSTR. from Amer. * SHORELINE ANCHOR PT. ponds and other non-tidal waters STREAM FLOW ANCHOR PT. Layout NOTE: ANCHORING WITH BUOYS. 2' STANDARD CONTAINMENT SYSTEMS LIGHT BUOY 5' ANCHOR (AS RECOMMENDED BY THE MANUFACTURER) 5' WATER SURFACE MIN. THE CURTAIN WILL NOT SINK FROM WIND OR CURRENT LOADS.3 Sheet 5 of 8 12/03 Date: _________________ .5. HENCE. REMOVES ALL VERTICAL FORCES FROM THE CURTAIN.Standard Detail & Specifications Turbidity Curtain NOTE: The alternative layout shown is intended for tidal waters and/or heavy wind and wave action FLOOD EBB LIMITS OF CONSTR.Alt. TYP EXISTING SHORELINE ANCHOR & ANCHOR BUOY BARRIER MOVEMENT DUE TO TIDAL CHANGE SHORELINE ANCHOR PT. AS SHOWN. 12" CURTAIN RIVERBED Additional Requir ements for Navigable W aters Requirements Waters Source: Adapt. 100' T YP. TC-(1/2/3) (Std/Alt) DE-ESC-3. Symbol: Detail No. * ' * 100 . BUOY AUTOMATIC FLASHING LIGHT (ON AT DUSKOFF AT DAWN) 100' ON CENTER SHALL BE USED IN NAVIGABLE CHANNELS ONLY ATTACH LINES TO SHACKLE MIN. SHORELINE ANCHOR PT. from Amer. Boom and Barrier Corp. FILL AREA * THIS DISTANCE IS VARIABLE Plan . The anchor line should then run from the buoy to the to load line of the curtain.3 Sheet 6 of 8 12/03 Date: _________________ . manufacturer's recommendations should be followed. The curtain fabric shall meet manufacturer's recommendations for the application. Materials a.000 pounds. Boom and Barrier Corp. Bottom anchors must be sufficient to hold the curtain in the same position relative to the bottom of the watercourse without interfering withthe action of the curtain. g.x 4-inch or 2-1/2-inch minimum diameter wood or 1. from Amer. Seams in the fabric shall be either vulcanized welded or sewn and shall develop the full strength of the fabric. Additional anchorage shall be provided as necessary. As previously noted. External anchors may consist of wooden or metal stakes (2. c. plow or fluke-type) or may be weighted (mushroom type) and should be attached to a floating anchor buoy via an anchor line. Type II and Type III must have load lines also fabricated into the top of the fabric.33 lbs/linear foot steel) when Type I installation is used. anchor spacing will vary with current velocity and potential wind and wave action. Floatation devices shall be flexible. See detail for orientation of external anchors and anchor buoys for tidal installations. e. when Type II or Type III installations are used. d. these lines must contain enough slack to allow the buoy and curtain to float freely with tidal changes without pulling the buoy or curtain down and must be checked regularly to make sure they do not become entangled with debris.5.Standard Detail & Specifications Turbidity Curtain Construction Notes: 1. When used with Type III installations. TC-(1/2/3) (Std/Alt) DE-ESC-3. b. Buoyancy provided by the floatation units shall be sufficient to support the weight of the curtain and maintain a freeboard of at least 3 inches above the water surface level. Symbol: Detail No. buoyant units contained in an individual floatation sleeve or collar attached to the curtain. The supplemental (bottom) load line shall consist of a chain incorporated into the bottom hem of the curtain of sufficient weight to serve as ballast to hold the curtain in a vertical position. Barriers should be a bright color (yellow or "international" orange are recommended) that will attract the attention of nearby boaters. Load lines must be fabricated into the bottom of all floating turbidity curtains. f. The load lines shall have suitable connecting devices which develop the full breaking strength for connection to load lines in adjacent sections as shown in the detail. Source: Adapt. The top load line shall consist of woven webbing or vinyl-sheathed steel cable and shall have a break strength in excess of 10. The anchor may dig into the bottom (grappling hook. bottom anchors should be used. In such situations. Boom and Barrier Corp. Turbidity curtain shall not be installed across channel flows unless there is a danger of causing sediment deposition to occur in the middle of a watercourse. from Amer. Before unfurling. In the calm water of lakes or ponds (Type I installation) it is usually sufficient to set the curtain end stakes or anchor points (using anchor buoys if bottom anchors are employed). Following this. Symbol: Detail No. d. Attaching the anchors to the bottom of the curtain could cause premature failure of the curtain due to the stresses imparted on the middle section of the curtain.5. then tow the curtain in the furled condition out and attach it to the stakes or anchor points.3 Sheet 7 of 8 12/03 Date: _________________ . confining most of the silt-laden water to the work area inside the "V" and directing it to the shoreline. prior to putting the furled curtain into the water. TC-(1/2/3) (Std/Alt) DE-ESC-3. the curtain may be installed so as to form a long-sided. The anchoring line attached to the flotation device on the downstream side will provide support for the curtain. the furling lines may be cut to allow the skirt to drop.) 2. c. In no case shall the curtain be installed perpendicular to the channel flow. Once the location has been deemed adequate. Anchor buoys should be employed on all anchors to prevent the current from submerging the flotation at the anchor points. Care must be taken to ensure that anchor points are of sufficient holding power to retain the curtain under the existing current conditions. sharp "V" to deflect clean water around a work site. In rivers or in other moving waters (Type II and Type III installations) it is important to set all curtain anchor points. thereby blocking access or creating a sand bar. Source: Adapt. any additional stakes or buoyed anchors required to maintain the desired location of the curtain may be set and these anchor points made fast to the curtain.Standard Detail & Specifications Turbidity Curtain Construction Notes (cont. anchors should be provided on both sides of the curtain. Anchor lines should be attached to the flotation device. the "lay" of the curtain should be assessed and any necessary adjustments made to the anchors. b. Only then shall the furling lines be cut to allow the curtain skirt to drop. not to the bottom of the curtain. If the curtain is being installed into tidal areas which would be subject to currents in both directions. After the anchors have been secured. the furled curtain should be secured to the upstream anchor point and then sequentially attached to each next downstream anchor point until the entire curtain is in position. This will minimize curtain movement and prevent the curtain from overrunning the anchors during tide reversals. Installation a. Standard Detail & Specifications Turbidity Curtain Construction Notes (cont. c. Care shall be taken to protect the skirt from damage as the turbidity curtain is dragged from the watercourse. Removal a. When the curtain is no longer required as determined by the inspector. broken cement. so as to minimize damage when hauling the curtain over the area. from Amer. etc. The manufacturer's instructions must be followed to ensure the adequacy of the repair. repair kits are generally available from the manufacturer. Boom and Barrier Corp. b. Remaining sediment shall be sufficiently settled before removing the curtain. The site selected to bring the curtain ashore should be free of sharp rocks. TC-(1/2/3) (Std/Alt) DE-ESC-3. the curtain and related components shall be removed in such a manner as to minimize turbidity. Should repairs to the geotextile fabric become necessary. If the curtain has a deep skirt. Source: Adapt. c. Maintenance a. Sediment may be removed and the original depth (or plan elevation) restored. it can be further protected by running a small boat along its length with a crew installing furling lines before attempting to remove the curtain from the water. b. debris. The individual(s) identified on the plan as responsible for maintenance of the curtain shall do so for the duration of the project in order to ensure the continuous protection of the watercourse. Symbol: Detail No. 4.5.) 3. Any spoils must be taken to an approved upland disposal area and stabilized in accordance with the approved plan.3 Sheet 8 of 8 12/03 Date: _________________ . 6 3. 2. and sanitary wastes. the likelihood of water quality impacts increases.STANDARD AND SPECIFICATIONS FOR CONSTRUCTION SITE POLLUTION PREVENTION Definition: Practices which are intended to control non-sediment pollutants associated with construction activities. For example.1 . fertilizers used for vegetative stabilization.1 12/03 . These pollutants include pesticides (insecticides. all contribute to pollutant loadings. soil infiltration rates. sealers. wood. potential pollution associated with fertilizer usage may be greater along a highway or at a housing development than it would be at a shopping center development because highways and housing developments usually have greater landscaping requirements. and frequency of rainfall. The proximity of surface waters to the nonpoint pollutant source. As the distance separating pollutantgenerating activities from surface waters decreases. and paints. gasoline. such as the amount.000 square feet. intensity. The physical characteristics of the construction site. and asphalt degreasers). The majority of all pollutants generated at construction sites are carried to surface waters via runoff. Planning Considerations: Many potential pollutants other than sediment are associated with construction activities. herbicides.6. garbage. Purpose: To prevent the generation of nonpoint source pollution from construction sites due to improper handling and usage of nutrients and toxic substances. and to prevent the movement of toxic substances from the construction site. The variety of pollutants present and the severity of their effects are dependent on a number of factors: 1. surface roughness. petrochemicals (oils. and area denuded. the factors affecting runoff volume. paper. 3. wash water associated with these products. and rodenticides). slope length and steepness. Conditions Where Practice Applies All earth disturbing activities which disturb greater than 5. fungicides. Therefore. The nature of the construction activity. construction chemicals such as concrete products. use. using plastic sheeting to line the storage area. Keep tanks off the ground. follow these guidelines: a.2 . and local regulations that govern their usage. methods that are the least disruptive to the environment and human health should be used first. Waste oil for recycling should not be mixed with degreasers. 1. Containers should be triple-rinsed before disposal. Establish fuel and vehicle maintenance staging areas located away from all drainage courses. apply. 2. 3. checking containers periodically for leaks or deterioration. tightly closing lids. and dispose of petroleum products. and paper dropped into oils and lubricants should be disposed of in proper receptacles or recycled. dry place. and f. Keep lids securely fastened. in accordance with the law. When storing petroleum products. storage. cans. and notifying neighboring property owners prior to spraying.Practices The practices set forth below have been found by EPA to be representative of the types of practices that can be applied successfully to achieve the management measure described above. Pesticide storage areas on construction sites should be protected from the elements. Clearly label all products. and design these areas to control runoff. Pesticides and herbicides should be used only in conjunction with Integrated Pest Management (IPM). c. handling. Create a shelter around the area with cover and wind protection. Other practices include setting aside a locked storage area. antifreeze. rags. Properly store. maintaining a list of products in storage. storage. Application rates should conform to registered label directions. State. Warning signs should be placed in areas recently sprayed or treated. solvents. storing in a cool. Properly store. d. Oil and oily wastes such as crankcase oil. 6 12/03 3. or brake fluid.6. and disposal. Proper maintenance of equipment and installation of proper stream crossings will further reduce pollution of water by these sources.1 . and dispose of pesticides. Pesticides should be disposed of through either a licensed waste management firm or a treatment. e. Pesticides should be the tool of last resort. and rinse waters should be reused as product. Create an impervious berm around the perimeter with a capacity 110 percent greater than that of the largest container. Line the storage area with a double layer of plastic sheeting or similar material. b. Stream crossings should be minimized through proper planning of access roads. Disposal of excess pesticides and pesticide-related wastes should conform to registered label directions for the disposal and storage of pesticides and pesticide containers set forth in applicable Federal. handle. Persons mixing and applying these chemicals should wear suitable protective clothing. handle. and disposal (TSD) facility. and wash water may be discharged into sanitary sewers if solids are removed from the solution first. or surface water.1 . Maintain and wash equipment and machinery in confined areas specifically designed to control runoff. open ditch. Cover the spill with absorbent material such as kitty litter or sawdust. A location not subject to urban runoff and more than 50 feet away from a storm drain. Do not discharge any solvents into sewers. Materials for cleaning up spills should be kept on site and easily available. or steam cleaning. which can then be reused or recycled. c. 6 3. 9. b. including topsoil and chemicals. Never dump washout into a sanitary sewer or storm drain.) Small parts can be cleaned with degreasing solvents. Spill control plan components should include: a. but do not use straw. 7.3 12/03 . Contain any liquid. Spills should be cleaned up immediately and the contaminated material properly disposed of. and then can be placed in a dumpster. Using soil tests to determine specific nutrient needs at the site can greatly decrease the amount of nutrients applied. can be broken up. cover. b. including excess asphalt. Use alternative methods for cleaning larger equipment parts. and isolate construction materials. produced during construction. 5. and work fertilizers and liming materials into the soil to depths of 4 to 6 inches. An area where the concrete wash can harden. Washout from concrete trucks should be disposed of into: a. Thinners or solvents should not be discharged into sanitary or storm sewer systems when cleaning machinery. d. to prevent runoff of pollutants and contamination of ground water. Store. Stop the source of the spill. Educate construction workers about proper materials handling and spill response procedures. 6. Develop and implement a spill prevention and control plan. such as high-pressure. Properly time applications. (This practice should be verified with the local sewer authority. 8. or c. Equipment-washing detergents can be used. Distribute or post informational material regarding chemical control. Provide sanitary facilities for constructions workers. or onto soil or pavement that carries urban runoff. high-temperature water washes. Post spill procedure information and have persons trained in spill handling on site or on call at all times.6. Provide adequate disposal facilities for solid waste. 10. Dispose of the used absorbent properly. A designated area that will later be backfilled.4. Develop and implement nutrient management plans. 6.4 . 6 12/03 3.1 .This page left intentionally blank. 840-B-92-002 Symbol: Detail No. f. d. When possible. Substances shall not be mixed. e. Manufacturers’ instructions for disposal shall be strictly adhered to. Source: Adapted from USEPA Pub. Concrete Detergents Paints (enamel and latex) Cleaning solvents Pesticides Wood scraps Fertilizers Petroleum based products 2. e. or more if necessary. 3. The licensed trash hauler is responsible for cleaning out dumpsters. The dumpsters shall be emptied a minimum of twice per week. DE-ESC-3. c. All materials shall be stored in a neat. c. b. all of a product shall be used up prior to disposal of the container.1 Sheet 1 of 3 6/05 Date: _________________ . Waste management practices a. Waste materials shall be salvaged and/or recycled whenever possible. The site foreman shall designate someone to inspect all BMPs daily. b. h. g. orderly manner in their original labeled containers and covered.6. Material Inventory Document the storage and use of the following materials: a.Standard Detail & Specifications Site Pollution Prevention Notes: The Construction Site Pollution Prevention Plan should include the following elements: 1. Good housekeeping practices a. f. c. All waste materials shall be collected and stored in securely lidded dumpsters in a location that does not drain to a waterbody. b. Store only enough product required to do the job. d. d.) d. g. 840-B-92-002 Symbol: Detail No. antifreeze.Standard Detail & Specifications Site Pollution Prevention Notes (cont. If fertilizer bags can not be stored in a weather-proof location. 4. Recycle bins shall be placed near the construction trailer.6. pipes and other equipment as necessary. b. valves. Spill prevention practices a. Washout from concrete trucks shall be disposed of in a temporary pit for hardening and proper disposal. equipment should be taken to off-site commercial facilities for washing and maintenance. vehicles shall be washed with high-pressure water spray without detergents in an area contained by an impervious berm. f. e. Source: Adapted from USEPA Pub. e. If performed on-site. solvents and tires shall be disposed of in accordance with manufacturers’ recommendations and local.1 Sheet 2 of 3 6/05 Date: _________________ . Potential spill areas shall be identified and contained in covered areas with no connection to the storm drain system. Equipment maintenance practices a. Trash shall be disposed of in accordance with all applicable Delaware laws. Drip pans shall be used for all equipment maintenance. 5. Fuel nozzles shall be equipped with automatic shut-off valves. Trash cans shall be placed at all lunch spots and littering is strictly prohibited. If possible. pumps. d. c. All used products such as oil. c. DE-ESC-3. Low or non-toxic substances shall be prioritized for use. Warning signs shall be posted in hazardous material storage areas. state and federal laws and regulations. they shall be kept on a pallet and covered with plastic sheeting which is overlapped and anchored. Preventive maintenance shall be performed on all tanks. b. Equipment shall be inspected for leaks on a daily basis. f. 6. Contact information for reporting spills through the DNREC 24-Hour Toll Free Number shall be prominently posted.) e.1 Sheet 3 of 3 6/05 Date: _________________ . Education a. b. Information regarding waste management. DE-ESC-3. 840-B-92-002 Symbol: Detail No. CONTACT INFORMATION DNREC 24-Hour Toll Free Number 800-662-8802 DNREC Solid & Hazardous Waste Branch 302-739-9403 Source: Adapted from USEPA Pub. 6. Best management practices for construction site pollution control shall be a part of regular progress meetings. equipment maintenance and spill prevention shall be prominently posted in the construction trailer.Standard Detail & Specifications Site Pollution Prevention Notes (cont. Source: Symbol: Detail No.Standard Detail & Specifications Site Pollution Prevention This page left intentionally blank. 6/05 Date: _________________ . in large part. They should be inspected twice a week and after each rainfall event. Also identify areas where you want to limit construction traffic. Evaluate the site. Do so as soon as possible. Among the more commonly used practices are vegetative stabilization. Identify trees that you want to save and vegetation that will remain during construction. When a problem is identified. stabilized construction entrances. the principles and methods for controlling erosion and reducing off-site sedimentation are relatively simple and inexpensive. However.1 . Determine the specific ones needed. on the lot’s natural features. repair the practice immediately. Purpose: To prevent soil from eroding from a site and damaging adjacent properties or degrading nearby watercourses. silt fence. Conditions Where Practice Applies: This standard was primarily developed for sites that qualify for the issuance of a Standard Plan and which therefore lack detailed Erosion & Sediment Control Plans. Revegetate the site. 6 3. Wherever possible. 4. Location of structures should be based. Usually. 2. 3. and install them before clearing the site. The following are four basics to be followed when developing a building site. A well-maintained lot has a higher sale potential.1 12/03 . and runoff inlet protection. Select and install erosion/sediment control practices.STANDARD AND SPECIFICATIONS FOR ESC FOR MINOR DEVELOPMENT Definition: Guidelines for controlling erosion and sediment during the development of relatively small sites.7. Inventory and evaluate the resources on the lot before building. Also. the guidelines may also be applicable for controlling individual lots within larger sites having such plans. Do not flush sediment from the street with water. Maintenance of all practices is essential for them to function properly. any sediment that is tracked onto the street must be scraped and deposited in a stable area. 1. preserve existing vegetation to help control erosion and off-site sedimentation. Develop a practice maintenance program. Planning Considerations: Erosion control is important on any building site regardless of its size. Before construction. d. burn. or park vehicles near trees or in areas marked for preservation. An individual plan should be developed for specific site conditions which preclude the use of this standard. 6 12/03 3. Surface drainage a. Avoid filling in existing drainage channels and roadside ditches. and vegetation suitable for filter strips. 1. Protect trees and sensitive areas To prevent root damage. a. around the area designated for a septic system absorption field (if applicable). Evaluate the site. Place a physical barrier. Divert storm water runoff away from the structure by grading the lawn in accordance with local building code requirements. place soil piles. on-site septic system absorption fields. Position the structure a minimum of 18 inches above street level. such as plastic fencing. With proper planning. then reconnect it. especially in perimeter areas. reroute it (using the equivalent pipe size) around the structure or septic field. marking for protection any important trees and associated rooting zones. b. since that could result in wetness problems on someone else’s property and/or damage to adjacent road surfaces.Guidelines for Building Lot Drainage The best time to provide for adequate lot drainage is before construction begins.7. Subsurface drainage a. Identify vegetation to be saved Select and identify the trees. b. assume that it carries water even if currently dry. c.2 . If an existing field drainage tile is accidentally cut. most drainage problems can be avoided. do not grade. 2. and other vegetation that you want to save (see “Vegetative Filter Strips” under Step 2). shrubs. evaluate the entire site. therefore.1 . Correcting a problem after it occurs is usually much more difficult and costly. 1. Provide an outlet for foundation or footer drains and for general lot drainage by using storm sewers (where allowed). or obtain drainage easements if you must cross adjoining properties. unique areas to be preserved. Construct side and rear yard swales to take surface water away from the structure. Construction Sequence for Building Site Erosion Control Practices It is important to note that the following construction sequence is meant to be for illustrative purposes only and may not be applicable for all building lots. b. Place plastic mesh or snow fence barriers around the trees’ dripline to protect the area below their branches. The following are some guidelines to ensure good lot surface and subsurface drainage. Construct the home and install the utilities. ditch. Inspect the control practices a minimum of twice a week and after each storm event. Add the extenders as soon as the gutters and downspouts are installed. and install perimeter controls to minimize the potential for off-site sedimentation. lake. or drainageway. Protect storm drain inlets. sidewalk. Prepare the site for construction and for installation of utilities. Build the structure(s) and install the utilities. Install downspout extenders Downspout extenders are highly recommended as a means of preventing lot erosion from roof runoff. also install the sewage disposal system and drill the water well (if applicable). Make sure all contractors (especially the excavating contractor) are aware of areas to be protected. 5. 7. Identify the areas where sediment-laden runoff could leave the construction site. Maintain all erosion and sediment control practices until construction is completed and the lot is stabilized. d. Be sure the extenders have a stable outlet. Remove subsoil and stockpile separately from the topsoil. Toward the end of each work day. clean up any soil washed off-site. wetland. Install inlet protection on nearby storm drain inlets.1 . c.3 12/03 . Protect down-slope areas with silt fence. Use silt fencing along the perimeter of the lot’s downslope side(s) to trap sediment. stream. preserve a 20 to 30 foot wide vegetative buffer strip around the perimeter of the property. a. then consider the following. making any needed repairs immediately. and use it as a filter strip for trapping sediment. b. Locate the stockpiles away from any downslope street. 4. b.7. such as the street. a. Protect down-slope areas with vegetative filter strips. Do not flush areas with water. Do not mow filter strip vegetation shorter than 4 inches. It’s important that perimeter controls are in place before any other earth-moving activities begin. 6 3. On slopes of less than 6 percent. Maintain the control practices. Install perimeter erosion and sediment controls. temporary-seed the stockpiles with annual rye and/or place silt fence around the perimeter of the piles. 3. Prepare the site for construction.2. or a well vegetated area. By the end of the next work day after a storm event. Immediately after stockpiling. Restrict all lot access to a stabilized entrance to prevent vehicles from tracking mud onto roadways. sweep or scrape up any soil tracked onto roadways. Salvage and stockpile the topsoil/subsoil Remove topsoil (typically the upper 4 to 6 inches of soil material) and stockpile. 6. driveway. Contact local seed suppliers or professional landscaping contractors for recommended seeding mixtures and rates. Spread straw mulch on newly seeded areas. Immediately after all outside construction activities are completed. anchor the mulch by crimping it 2 to 4 inches into the soil or use a tackifer (adhesive binder). (Or shorten to outlet onto the vegetated areas.4 . a. Reference: Indiana Dept. Less watering is needed once grass is 2 inches tall. On steep slopes. anchor the mulch with netting or tackifiers. Silt fence. remove any remaining temporary erosion and sediment control practices. of Natural Resources. Seed or sod bare areas. Spread the stockpiled topsoil to a depth of 4 to 6 inches over roughgraded areas. Once the sod and/or vegetation is well established. Follow recommendations of a professional landscaping contractor for installation of sod. "Erosion Control for the Home Builder" (1/96) 6 12/03 3. stabilize the lot with sod or seed and straw mulch. Revegetate the building site. Fertilize and lime according to soil test results or recommendations of a seed supplier or a professional landscaping contractor. Water newly seeded/sodded areas every day or two to keep the soil moist. Storm drain inlet protection measures. c. allowing for maximum infiltration). An alternative to anchored mulch would be the use of erosion control blankets. Spread the stockpiled subsoil to rough grade. such as: a. b. Redistribute the stockpiled subsoil and topsoil. Division of Soil Conservation. 9.8. Remove remaining temporary control measures. c. Mulch newly seeded areas.1 .7. b. using 1 to 2 bales of straw per 1.000 square feet. On flat or gently sloping land. Downspout extenders. DE-ESC-3.Standard Detail & Specifications ESC for Minor Development Property Line (Typ.) IP-1 SF SF TP SF Stockpile s SF Downspout Extender (Typ.Type 2 IP-2 SF TP SCE Symbol: Detail No.7.1 Sheet 1 of 2 12/03 Date: _________________ .Type 1 IP-1 Inlet Protection . "Erosion Control for the Home Builder" t LEGEND Inlet protection .) TP s Proposed Structure t SF SF t SCE t SF IP-2 Flow Silt Fence Tree Protection Stabilized Construction Entrance Source: Adapted from IN DNR. Prepare the Site for Construction. b. Install Perimeter Erosion And Sediment Controls. Salvage and Stockpile the Topsoil/Subsoil 5. making any needed repairs immediately. 8. Source: Adapted from IN DNR. Protect Trees and Sensitive Areas 2. Identify Vegetation To Be Saved b. a. Protect down-slope areas with vegetative filter strips. Evaluate the Site.7. b. Inspect the control practices a minimum of twice a week and after each storm event. Install Downspout Extenders 7. 3. a. b. Install inlet protection on nearby storm drain inlets. Seed or sod bare areas. Build the Structure(s) and Install the Utilities. Restrict all lot access to stabilized construction entrance to prevent vehicles from tracking mud onto roadways.Standard Detail & Specifications ESC for Minor Development Construction Notes: 1. c. DE-ESC-3. a. Protect down-slope areas with silt fence. Mulch newly seeded areas. "Erosion Control for the Home Builder" Symbol: Detail No. Maintain the Control Practices. d. Redistribute the stockpiled subsoil and topsoil. 4. Maintain all erosion and sediment control practices until construction is completed and the lot is stabilized. 9.1 Sheet 2 of 2 12/03 Date: _________________ . c. 6. Remove Remaining Temporary Control Measures. Revegetate the Building Site. a. 7. The more a tree is protected from the wind. a.STANDARD AND SPECIFICATIONS FOR TREE PROTECTION Definition: Protection of desirable trees from mechanical and other injury while the land is being developed. Such superficial wounds provide access to insects and disease. Conditions Where Practice Applies: On developing sites that have desireable trees. Excessive pruning .2 . Construction activities expose trees to a variety of stresses resulting in injury ranging from superficial wounds to death. 6 3. Purpose: To provide protective measures that are necessary to insure the survival of desireable trees. decay may set in. 1. If the pruning is done without considering the growth habit. The result of improper thinning is often wind-thrown trees. c.Unprotected trees are often “topped” or carelessly pruned to prevent interference with utility wires or buildings. Trees tend to develop anchorage where it is most needed. Selective removal in favor of a single tall tree may also create a lightning hazard.1 12/03 . b. If too many branches are cut. the tree may lose all visual appeal. the less secure is its anchorage. Wind damage . food processing. Planning Considerations: Trees may appear to be inanimate objects. Surface Impacts: Natural and man-related forces exerted on the tree above the ground can cause significant damage to trees.Tree trunks are often nicked or scarred by trucks and construction equipment. An understanding of these stresses is helpful in planning for tree protection.Removal of some trees from groups will expose those remaining to greater wind velocities. the tree may not be able to sustain itself. Trunk damage . If the branches are not pruned correctly. Isolated trees develop anchorage rather equally all around. but they are living organisms that are constantly involved in the process of respiration. with stronger root development on the side of the prevailing winds. and growth. Construction chemicals or refuse disposed of in the soil can change soil chemistry or be toxic to trees. younger trees of desirable species are preferred. if the cost of preservation is greater than the cost of replacement with a specimen of the same age and size. or paving can block off air and water from roots. The mass of the root system is the correct size to balance the intake of water from the soil with the transpiration of water from the leaves. Long-lived specimens that are past their prime may succumb to the stresses of construction. Deep cuts may sever a large portion of the root system. and maple. a number of criteria must be considered. a. d. roots. Compaction of the soil within the drip line (even a few feet beyond the drip line) of a tree by equipment operation. and located on a topographical map.2. c. Lowering the grade may lower the water table. h. However. beech. e. and the rest of the tree can damage or kill a tree. Base decisions on which trees to save on the following considerations: 1. oxygen. Raising the grade as little as 6 inches can retard the normal exchange of air and gases. Roots may suffocate due to lack of oxygen. Most damage to trees from construction activities is due to the invisible root zone stresses. However. However. This can cause drowning of the deeper roots. b. such as white oak. removing some feeder roots and exposing the rest to drying and freezing. materials storage.2 . so smaller. replacement may be preferred. even shallow cuts of 6 to 8 inches will remove most of the topsoil.2 . or be damaged by toxic gases and chemicals released by soil bacteria. in planning for the development of where some trees will be preserved. Selecting Trees to be Retained The proper development of a wooded site requires completion of a plan for tree preservation before clearing and construction begins. Lowering the grade is not usually as damaging as raising it. Raising the grade may also elevate the water table. Trees suffering such damage usually die within 2 to 5 years. Root Zone Impacts: Disturbing and delicate relationship between soil. The roots of an existing tree are established in an area where essential materials (water. Life expectancy and present age: Preference should be given to trees with a long life span. they are more resilient and will last longer. either as stands or as individuals. 6 12/03 3. depending on the density and value of the trees. This is a problem in large roadway cuts or underdrain installations. depriving the tree of water and increasing the chance of wind-throw.7. Design Criteria: No formal design is required. f. inducing drought. and nutrients) are present. g. Trenching or excavating through a tree’s root zone can eliminate as much as 40 percent of the root system. Trees should be identified by species. bark. and underground drainage. septic tanks. and attractive flowers and fruit are desirable characteristics. Survival needs of the tree: Chosen trees must have enough room to develop naturally. salt tolerant species for areas exposed to deicing salts or ocean spray. As trees mature. Trees standing alone generally have higher landscape value than those in a wooded situation. A clean tree is worth more than a dirty one. and other paved surfaces. or plant exudates. 5. they may interfere with proposed structures and overhead utilities. However. Determine the effect of proposed grading on the water table. They will be subject to injury from increased exposure to sunlight. b. patios. tree groups are much more effective in preventing erosion and excess stormwater runoff. Roots may interfere with walls. 4. allowing the sun to warm buildings and soil.7. Trees which seed prolifically or sucker profusely are generally less desirable in urban areas. they can be thinned gradually. 7. Aesthetic values: Handsome bark and leaves. It is best to retain groups of trees rather than individuals. Trees that provide interest during several seasons of the year enhance the value of the site. fruit. Comfort: Trees help relieve the heat of summer and buffer strong winds throughout the year. and wind. Gases generated in them can travel long distances underground. select trees which are pollution-tolerant for high-traffic and industrial areas. Health and disease susceptibility: Check for scarring caused by fire or lightning. large trees with overhanging limbs that endanger property. Pest and pollution-resistant trees are preferred. 3. Thornless varieties are preferred. Open grown trees often have better form than those grown in the woods. driveways. 9. d. Wildlife: Preference should be given to trees that provide food. cover. 6 3. Consider the mature height and spread of trees. insect or disease damage. and rotted or broken trunks or limbs. Cleanliness: Some trees such as elm and black locust are notoriously “dirty". neat growth habit.2. Consider location of landfills. trees with brittle wood (such as silver maple). Deciduous trees drop their leaves in winter. Trees must be appropriate to the proposed use of the development. and small crowns at the top of tall trunks. 8. Relationship to other trees: Individual species should be evaluated in relation to other species on the site. walks. c. misshapen trunks or crowns. fine fall color. trees growing from old stumps. 10. Adaptability to the proposed development: a.3 12/03 . and nesting sites for birds and game.2 . to injure distant trees. Choose species tolerant of anaerobic soil conditions. Structure: Check for structural defects that indicate weakness or reduce the aesthetic value of a tree. A species with low value when growing among hardwoods will increase in value if it is the only species present. Trees with strong tap or fibrous root systems are preferred to trees with weak rooting habits. dropping twigs. Grading should not take place within the drip line of any tree to be saved. heat radiated from buildings and pavement. 6. Summer temperatures may be 10 degrees cooler under hardwoods than under conifers. screen and buffer trees for noise or objectionable views. or water lines. Evergreens are more effective wind buffers. Specifications: 1. 3. 7.7. No tree should be destroyed or altered until the design of buildings and utility systems is final. a surveyor’s ribbon or a similar material applied at a reasonable height encircling the tree will suffice. 3. and located where they will not cause compaction over roots. the limits of clearing shall be located outside the drip line of any tree to be retained and. Locate erosion and sediment control measures at the limits of clearing and not in wooded areas. such as flood plains. Critical areas. Locate roadways to cause the least damage to valuable stands. steep slopes. Pre-construction Conference: During any preconstruction conference. 5. 6 12/03 3. to minimize cuts and fills. select trees to be saved before siting the building. Construction material storage areas and worker parking should be noted on the site plan. In most situations. if possible.” Individual specimens that are not part of a tree group shall also have their species and diameter noted on the plan.4 . Location: Groups of trees and individual trees selected for retention shall be accurately located on the plan and designated as “tree(s) to be saved. 2. Limits: At a minimum. If lot size allows. Sediment basins should be constructed in the natural terrain. in no case. Marking: Prior to construction and before the preconstruction conference. 6. leave enough ground ungraded beyond the drip line of the tree to allow for its survival. 4. and wetlands. tree preservation and protection measures should be reviewed with the contractor as they apply to that specific project. to prevent deposition of sediment within the drip line of trees being preserved. individual trees and stands of trees to be retained within the limits of clearing shall be marked at a height visible to equipment operators. such as an area which is supposed to receive formal landscaping. When retaining existing trees in parking areas. where feasible. 2. Excavations for basements and utilities should be kept away from the drip line of trees. rather than in locations where extensive grading and tree removal will be required. closer than 5 feet to the trunk of any tree. A diagonal slash of brightly colored paint approximately 8 to 10 inches in length is a common practice in areas where an accidental or purposeful alteration of the proper markings is a concern. Follow original contours. should be left in their natural condition or only partially developed as open space.Site Planning for Tree Protection: 1. Minimize trenching by locating several utilities in the same trench. 4.2 . vehicular traffic. or stockpiles of any construction materials (including topsoil) shall not be permitted within the drip line of any tree to be retained. pushed or pulled into trees being retained.2 . gypsum board. Equipment Operation and Storage: Heavy equipment. 7.) Maintenance: Fencing and armoring devices shall be in place before any excavation or grading is begun. 6 3. Fires: Fires shall not be permitted within 100 feet from the drip line of any trees to be retained. and lubricants shall not be disposed of in such a way as to injure vegetation. and shall be the last items removed during the final cleanup after the completion of the project. and kept under surveillance. Storage and Disposal of Toxic Materials: No toxic materials shall be stored closer than 100 feet to the drip line of any trees to be retained. Personnel must be instructed to honor protective devices. Paint. Fires shall be limited in size to prevent adverse effects on trees. trunk and tops of trees retained on the site. trees to be retained within 40 feet of a proposed building or excavation shall be protected by fencing. Fencing and Armoring: Any device may be used which will effectively protect the roots. nails. shall be kept in good repair for the duration of construction activities. chemicals. fuels. (See Standard Detail & Specifications for Tree Protection for suggested methods and materials. 6. Equipment operators shall not clean any part of their equipment by slamming it against the trunks of trees to be retained. However. 8.5 12/03 . wire.5. Trees being removed shall not be felled. acid.7. 7. 6 12/03 3.2 .6 .This page left intentionally blank. 2 Sheet 1 of 3 12/03 Date: _________________ . TP DE-ESC-3. Location of TTrree P rotection Protection Drip line Snow fence Board fence Cord fence Plastic fence Methods of TTrree P rotection Protection Source: Adapted from VA ESC Handbook Symbol: Detail No.Standard Detail & Specifications Tree Protection Drip line Protective device Limit of disturbance Proposed grading 5' Min.7. If it is not practical to erect a fence at the drip line.7. per 4-foot width (ASTM D638) c. trunk and tops of trees retained on the site. since the root zone within the drip line will still require protection. However. per 4-foot width (ASTM D638) b. Materials: 1.Board fencing consisting of 4-inch square posts set securely in the ground and protruding at least 4 feet above the ground shall be placed at the limits of clearing with a minimum of two horizontal boards between posts.Standard 40-inch high snow fence shall be placed at the limits of clearing on standard steel posts set 6 feet apart.000 lbs.40-inch high “international orange” plastic (polyethylene) web fencing secured to conventional metal “T” or “U” posts driven to a minimum depth of 18 inches on 6-foot minimum centers shall be installed at the limits of clearing.Standard Detail & Specifications Tree Protection Construction Notes: Any device may be used which will effectively protect the roots. The limits of clearing will still be located at the drip line. Chemical resistance: Inert to most chemicals and acids Source: Adapted from VA ESC Handbook Symbol: Detail No. The devices described are suggested only. Board Fence . TP DE-ESC-3. construct a triangular fence nearer the trunk. 2. trees to be retained within 40 feet of a proposed building or excavation shall be protected by fencing. Ultimate tensile yield: Average 2.2 Sheet 2 of 3 12/03 Date: _________________ . Personnel must be instructed to honor protective devices. Elongation at break (%): Greater than 1000% (ASTM D638) d. and are not intended to exclude the use of other devices which will protect the trees to be retained.900 lbs. Snow Fence . Plastic Fencing . The fence should have the following minimum physical qualities: a. 3. Tensile yield: Average 2. These additional trees shall be reexamined prior to the completion of construction and either be given sufficient treatment to ensure survival or be removed. 6.As a last resort.2 Sheet 3 of 3 12/03 Date: _________________ . Earth berms may not be used for this purpose if their presence will conflict with drainage patterns. However. TP DE-ESC-3.Additional trees may be left standing as protection between the trunks of the trees to be retained and the limits of clearing. Additional Trees . Cord Fence . Source: Adapted from VA ESC Handbook Symbol: Detail No. Earth Berms . 7. and shall be the last items removed during the final cleanup after the completion of the project. a tree trunk can be armored with burlap wrapping and 2-inch studs wired vertically no more than 2 inches apart to a height of 5 feet encircling the trunk.Posts with a minimum size of 2 inches square or 2 inches in diameter set securely in the ground and protruding at least 4 feet above the ground shall be placed at the limits of clearing with two rows of cord 1/4-inch or thicker at least 2 feet apart running between posts with strips of colored surveyor’s flagging tied securely to the string at intervals no greater than 3 feet. Trunk Armoring . the trunks of the trees in the buffer must be no more than 6 feet apart to prevent passage of equipment and material through the buffer.Temporary earth berms shall be constructed according to specifications for a Temporary Earth Dike with the base of the berm on the tree side located along the limits of clearing. 5. in order for this alternative to be used. Nothing should ever be nailed to a tree.Standard Detail & Specifications Tree Protection 4. the root zone within the drip line will still require protection. Maintenance: Fencing and armoring devices shall be in place before any excavation or grading is begun. If this alternative is used.7. shall be kept in good repair for the duration of construction activities. Standard Detail & Specifications Tree Protection This page left intentionally blank. 12/03 Date: _________________ . Source: Symbol: Detail No. 1 6/05 .Appendix A-1 Handbook Update Notices 6 A1 . 2 . 6 6/05 A1 .This page left intentionally blank. clarified min.ft.1.3 Sediment Trap .4.clarified temporary storage requirements DE-ESC-3.4.3.clarified temp.2 Stabilization Matting .4.updated contact phone numbers A-3 Geotextile Application Guide .Delaware ESC Handbook Update Notices Date 12/03 6/05 " " " " " " " " " " " " " " " " " " " " Description Initial release.2.4.4.1. flow-through rate for GD-II to 110 gpm/sq. stake dimensions 3.corrected staple pattern "E" DE-ESC-3.3.4 Temporary Sediment Basin .revised DE-ESC-3.added example products to GD-I A-3 Geotextile Application Guide .3.1 ROP-1 .clarified min. Acknowledgements .3.Slope .3 Riprap Outlet Sediment Trap .2 Slope Treatment .6.updated Sediment & Stormwater Program phone number 3.Channel .2 Stone Outlet Sediment Trap .clarified units to be used for surface area on Pg.1.1.5 Mulching .revised min. stake dimensions DE-ESC-3.added additional design charts 6 A1 . 3.increased spacing for S<2% DE-ESC-3.2 Reinforced Silt Fence . storage requirements DE-ESC-3.6. 3.corrected staple pattern "E" DE-ESC-3.increased spacing for S<2% DE-ESC-3.4-11 3.6 Check Dam .added note to depress centerline 3.1 Stabilization Matting .3 6/05 .2 Silt Fence .1.1 Site Pollution Prevention .clarified spacing requirements for benching 3. DG-2 Riprap Stilling Basin .10.5 Mulching .4.changed clean-out volume to 67 CY on Fig.1. stake dimensions DE-ESC-3.clarified min.6 Stone Check Dam .1.1 Silt Fence .4 Temporary Sediment Basin .6.clarified temporary storage requirements 3.2.3.1c 3.1.1.revised DE-ESC-3. 4 .Delaware ESC Handbook Update Notices Date Description 6 6/05 A1 . Appendix A-2 Glossary 6 A2 .1 12/03 . 6 12/03 A2 .This page left intentionally blank.2 . A facility placed at the entrance to a pipe conduit structure such as a drop inlet spillway or hood inlet spillway to prevent air from entering the structure when the pipe is flowing full. conservationist planners. clay.A device constructed around a pipe or other conduit and placed through a dam. Benthos .A general term for all detrital material deposited or in transit by streams.Areas of unconsolidated alluvium. and all variations and mixtures of these. a soil with a PH value less than 6. or river. etc. Acid soil . not completeness. 6 A2 .The process of building up a surface by deposition. It may be soft. including gravel. or dike for the purpose of reducing seepage losses and piping failures. silt.The maximum load that a material can support before failing. and probably of aluminum in proportion to hydroxylions. or at the toes of dams. Bentonite . Apron (soil engineering) . An example is the pavement below chutes. supporting the benthos.the official classification of soil materials and soil aggregate mixtures for highway construction used by the American Association of State Highway and Transportation Officials. Bearing capacity . soil with a PH value less than 7. Bedrock .The material used to refill a ditch or other excavation. nonetheless they are in common use in conservation matters.Soils developed from transported and relatively recently deposited material (alluvium) characterized by a weak modification (or none) of the original material by soil-forming processes. Anti-vortex device . Specifically. Acre-foot . Backfill . For most practical purposes. AASHTO classification . The terms are not necessarily used in the text.The volume of water that will cover 1 acre to a depth of 1 foot. alluvium is unconsolidated.The more or less solid rock in place either on or beneath the surface of the earth. Alluvial . levee. Alluvium . spillways.GLOSSARY The list of terms that follows is representative of those used by soil scientists. Anti-seep collar . This is a long-term or geologic trend in sedimentation.A floor or lining to protect a surface from erosion. sand.Pertaining to material that is transported and deposited by running water. and subject to flooding.The bottom of a body of water.A highly plastic clay consisting of the minerals montmorillonite and beidellite that swells extensively when wet. engineers. Unless otherwise noted. generally stratified and varying widely in texture. developers. Alluvial land . lake.6. Benthic region . recently deposited by streams. The aim of this Glossary is representativeness.A soil with a preponderance of hydrogen ions. or the process of doing so.0. medium or hard and have a smooth or irregular surface.3 12/03 . Aggradation . Alluvial soils .The plant and animal life whose habitat is the bottom of a sea. A ditch or channel excavated for the flow of water. minimize channel scour.Inlet to a drain in which entrance of water is by percolation rather than open flow channel. usually a subdivision of state government with a local government body and always with limited authorities. usually built at the curb line of a street. Catch basin . vegetation.Erosion prevention and stabilization of velocity distribution in a channel using jetties.A high-velocity. revetments. Compost . realignment. improvement and use of natural resources according to principles that will assure their highest economic or social benefits. Borrow area . having at its base a sediment sump designed to retain grit and detritus below the point of overflow. water.A chamber or well. Catchment . 6 12/03 A2 .Water temporarily stored in channels while en route to an outlet.The protection. Compaction . when unconfined.Small dam constructed in a gully or other small watercourse to decrease the streamflow velocity. the tendency of dry soil particles to attract moisture from wetter portions of soil.A natural stream that conveys water. that has undergone biological decomposition until it has become relatively stable humus. Chute .In soil engineering. Channel stabilization . Check dam . and promote deposition of sediment. Capillary action . Conservation District . use.In hydrology.A soil that. Cohesion .Surface drainage area.Organic residue or a mixture of organic residues and soil. Often called a soil conservation district or a soil and water conservation district. Cohesive soil .A source of earth fill material used in the construction of embankments or other earth fill structures. lining or other means in order to increase its capacity. the process by which the soil grains are rearranged to decrease void space and bring them into closer contact with one another. Conservation . drops. and related resource conservation.The improvement of the flow characteristics of a channel by clearing. has considerable strength when air-dried and significant cohesion when submerged. Channel . excavation. for the admission of surface water to a sewer or subdrain. and development within its boundaries. and other measures. Bottom lands . open channel for conveying water to a lower level without erosion.A narrow shelf or flat area that breaks the continuity of a slope. In Delaware there is a conservation district covering each county.Berm . Channel storage .A public organization created under state enabling law as a special-purpose district to develop and carry out a program of soil. exclusive of functional resistance.The capacity of a soil to resist shearing stress.A term often used to define lowlands adjacent to streams.4 . Blind inlet . Channel improvement . thereby increasing the weight of solid material per cubic foot. specifically fluid flow. narrow excavation constructed along the center line of a dam.An embankment to confine or control water.Process of earth moving by excavating part of an area and using the excavated material for adjacent embankments or fill areas. shrubs. rock. or aquifer. Cut . Cutoff trench . duration. or for retention of soil. or other hydraulic structures. 6 A2 . a levee. gravel.The period of time for which a facility is expected to perform its intended function.Contour . One may also speak of the discharge of a canal or stream into a lake. Detention dam . gallons per minute. Design storm . field. or millions of gallons per day.Screen or grate at the intake of a channel or a drainage or pump structure for the purpose of stopping debris. Debris dam . the flow of a stream. cubic meters per second. or other area needed protection from sediment accumulation. or other vegetation used for inducing deposition of silt and other debris from flowing water.The elevation of the water surface as determined by the flow conditions of the design floods.The theoretical time required to displace the contents of a tank or unit at a given rate of discharge (volume divided by rate of discharge).A dam constructed for the purpose of temporary storage of streamflow or surface runoff and for releasing the stored water at controlled rates. especially one built along the banks of a river to prevent overflow of lowlands.Managing stormwater runoff or sewer flows through temporary holding and controlled release. intensity. Discharge . Desilting area . to prevent gully erosion. to create a hydraulic head. (2) A line drawn on a map connecting points of the same elevation. or ocean. silt or other material.(1) An imaginary line on the surface of the earth connecting points of the same elevation.An area of grass. Detention time .A long. river. Detention .5 12/03 .The ratio of actual rate of flow to the theoretical rate of flow through orifices. and frequency that is used as a basis for design. levee or embankment and filled with relatively impervious material intended to reduce seepage of water through porous strata.(Engineering) . weirs. Design highwater . sand. located above a stock tank. dike. canal.A barrier built across a stream channel to retain rock.A barrier to confine or raise water for storage or diversion. Cut-and-fill . pond. Dam . Dike .Outflow. Cover crop . Critical area or site .A close-growing crop grown primarily for the purpose of protecting and improving soil between periods of permanent vegetation. Discharge coefficient (Hydraulics) . Design life . a volume of fluid passing a point per unit time commonly expressed as cubic feet per second. the depth below original ground surface of excavated surface. Debris guard . or other debris. (Hydraulics) Rate of flow.Sediment producing highly erodible or severely eroded areas.Portion of land surface or area from which earth has been removed or will be removed by excavating.A selected rainfall pattern of specified amount. resulting in small but significant periods of wetness. the more erodible it is. Soil . See Terrace. Diversion . soil drainage refers to the frequency and duration of periods when the soil is free of saturation. Soil . Moderately well drained . Diversion terrace .Excess water drains away rapidly and no mottling occurs within 36 inches of the surface. for example. A ditch (open drain) for carrying off surplus surface water or groundwater.Water is removed so slowly that the water table remains at or near the surface for the greater part of the time. Drainage .As a natural condition of the soil. Soil characteristics that affect natural drainage. Somewhat poorly drained . Drainage Divide .The removal of excess surface water or groundwater from land by means of surface or subsurface drains. or reduce the number of waterways. Generally speaking.Water is removed so slowly that the soil is wet for a large part of the time. and are sometimes used in connection with stripcropping to shorten the length of slope so that the strips can effectively control erosion.A geographical area or region that is so sloped and contoured that surface runoff from streams and other natural watercourses is carried away by a single drainage system by gravity to a common outlet or outlets. protect buildings from runoff. The soil has a black to gray surface layer with mottles up to the surface. Diversion dam . There may also be periods of surface ponding. Poorly drained .A channel with a supporting ridge on the lower side constructed across or at the bottom of a slope for the purpose of intercepting surface runoff. The following classes are used to express soil drainage: Well drained . which differ from terraces in that they consist of individually designed channels across a hillside.A buried pipe or other conduit (closed drain). may be used to protect bottomland from hillside runoff or may be needed above a terrace system for protection against runoff from an unterraced area. Mottling occurs between 0 and 8 inches. See Terrace. 6 12/03 A2 .6 . resulting in single-grain structure.Dispersion. Very poorly drained . Divide.A barrier built to divert part or all of the water from a stream into a different course. Drainage basin . Ease of dispersion is an important factor influencing the erodibility of soils. in poorly drained soils the root zone is waterlogged for long periods unless artificially drained.Water is removed from the soil slowly enough to keep it wet for significant periods but not all of the time. Strictly speaking. and the roots of ordinary crop plants cannot get enough oxygen. Drain .The boundary between one drainage basin and another. Mottling occurs between 18 and 36 inches. Drainage.Water is removed from the soil somewhat slowly.Diversions. in well-drained soils the water is removed readily but not rapidly. in excessively drained soils the water is removed so completely that most crop plants suffer from lack of water. excessively drained soils are a result of excessive runoff due to steep slopes or low available water-holding capacity due to small amounts of silt and clay in the soil material.The breaking down of soil aggregates into individual particles. Mottling occurs between 8 and 18 inches. Also referred to as a watershed or drainage area. the more easily dispersed the soil. They may also divert water out of active gullies. See Rill. or gravity. Environment .A structure for dropping water to a lower level and dissipating its surplus energy. Erodible . Normal erosion . vegetation. etc. Geological erosion . wind.7 12/03 . Synonymous to geological erosion. or other geological agents.The sum total of all the external conditions that may act upon an organism or community to in influence its development or existence.Dam constructed of compacted soil materials. Drop spillway .g. of animals or natural catastrophes that expose bare surfaces (e. or other material used to form an impoundment.The gradual erosion of land used by man which does not greatly exceed natural erosion. water table or piezometric surface (in groundwater flow) resulting from a withdrawal of water.A device used to reduce the energy of flowing water.. wind. removes the soil from this narrow area to considerable depths. or other natural agents under natural environmental conditions of climate. occurs mainly on recently disturbed and exposed soils. in some cases. Rill erosion .The wearing away of the land surface by running water.Drawdown . Embankment . primarily as a result of the influence of the activities of man or.A man-made deposit of soil. Channel erosion -The erosion process whereby the volume and velocity of a concentrated flow wears away the bed and banks of a well-defined channel.The normal or natural erosion caused by geological processes acting over long geologic periods and resulting in the wearing away of mountains. Gully erosion . Synonymous to natural erosion. a fall. fires).Erosion much more rapid than normal or geologic erosion. Drop structure . ice. the building up of floodplains. Erosion .Susceptible to erosion. ice. Detachment and movement of soil or rock fragments by water. Natural erosion . coastal plains.Lowering of the water surface (in open channel flow). Drop-inlet spillway . ranging from 1 to 2 feet to as much as 75 to 100 feet. See Natural Erosion. The drop may be vertical or inclined. rock.Outlet structure in which the water drops over a vertical wall onto an apron at a lower elevation.Wearing away of the earth’s surface by water.Outlet structure in which the water drops through a vertical riser connected to a discharge conduit. The following terms are used to describe different types of water erosion: Accelerated erosion . Earth dam . ice. including such processes as gravitational creep. Emergency spillway . etc.The erosion process whereby water accumulates in narrow channels and. over short periods. Energy dissipator . undisturbed by man.A vegetated earth channel used to safely convey flood discharges in excess of the capacity of the principal spillway..An erosion process in which numerous small channels only several inches deep are formed. 6 A2 . or other facilities for determining stream discharge.. Gage or gauge .g.Refers to wind or water having sufficient velocity to cause erosion. Gabion . natural. against erosion. discharge velocity. mouths of rivers. etc. pressure.A selected section of a stream channel equipped with a gage. Filter strip .A gate placed in a channel or closed conduit to keep out floodwater or tidal backwater.The removal of a fairly uniform layer of soil from the land surface by runoff water. Floodgate . e. Not to be confused with erodible as a quality of soil. Estuary .a grouping of erosion conditions based on the degree of erosion or on characteristic patterns. water level. salt marshes and lagoons). Gradation (geology) . Filter fabric . based on average probability of storms in the design region. Flood control .An overflow or inundation that comes from a river or other body of water. the term gradation refers to the frequency distribution of the various sized grains that constitute a sediment.Area where fresh water meets salt water.A rectangular or cylindrical wire mesh cage (a chicken wire basket) filled with rock and used as a protecting agent. narrow vegetative planting used to retard or collect sediment for the protection of watercourses... where the tide meets the river current (e.Methods of facilities for reducing flood flows. or other material. soil.A layer of sand and/or gravel designed to prevent the movement of fine-grained soils. Erosive . water-permeable material generally made of synthetic products such as polypropylene and used in stormwater management and erosion and sediment control applications to trap sediment or prevent the clogging of aggregates by fine soil particles.g. recorder.The anticipated period in years that will elapse. not to normal. wall thickness of steel pipe. etc. Flood . 6 12/03 A2 . Four erosion classes are recognized for water erosion and three for wind erosion. before a storm of a given intensity and/or total volume will recur. A measure of the thickness of metal. thus a 10year storm can be expected to occur on the average once every 10 years. by running water. Frequency of storm (design storm frequency) . The loosened and spattered particles may or may not be subsequently removed by surface runoff. Estuaries serve as nurseries and spawning and feeding grounds for large groups of marine life and provide shelter and food for birds and wildlife.Device for registering precipitation. temperature. Sewers designed to handle flows which occur under such storm conditions would be expected to be surcharged by any storms of greater amount of intensity. As used in connection with sedimentation and fragmental products for engineering evaluation.The bringing of a surface or a stream bed to grade. bays. or geological erosion. Applied to accelerated erosion.The spattering of small soil particles caused by the impact of raindrops on wet soils.A long. diameter of wire.Raindrop erosion . revetment. diversions. drainage basins or adjacent properties. Existing grade . Sheet erosion . Gaging station . Filter blanket . Erosion classes (soil survey) .The vertical location of the existing ground surface prior to cutting or filling.A woven or non-woven.8 . Any relatively high stream flow overtopping the natural or artificial banks in any reach of a stream. A gully may be dendritic or branching or it may be linear. with available discharge and with prevailing channel characteristics. on the surface of the earth.An incised channel or miniature valley cut by concentrated runoff but through which water commonly flows only during snow. Syn. Graded stream .A structure for the purpose of stabilizing the grade of a gully or otherwatercourse. A gully is sufficiently deep that it would not be obliterated by normal tillage operations. Gully control plantings .The height of water above any plane of reference. expressed as the vertical height through which a unit weight would have to fall to release the average energy possessed. narrow. or transplants in gullies to establish or re-establish a vegetative cover adequate to control runoff and erosion and incidentally produce useful products. or any combination thereof. Grade stabilization structure . or direction of flow. See erosion. or bottom of excavation.A member of the botanical family Gramineae.The slope of a road. changes in velocity. Head gate . Used in various compound terms such as pressure head. over a period of years. arroyo. possessed by each unit weight of a liquid. or natural ground. either kinetic or potential. Headwater . velocity head. Habitat .Water control structure. channel. 6 A2 . stockpiling. roadbed.The planting of forage. cutting. Grassed waterway . any surface prepared for the support of construction such as paving or the laying of a conduit.Energy loss due to friction.A stream in which.Any stripping.To finish the surface of a canal bed. or woody plant seeds. eddies. including the land in its cut-and-filled condition. the slope is delicately adjusted to provide. seedlings.The source of a stream. usually broad and shallow. or other characteristics per unit length. Hydrology . used to conduct surface water from an area at reduced flow rate.The science of the behavior of water in the atmosphere. cuttings.Change of elevation.9 12/03 .See erosion.Grade . covered with erosion-resistant grasses. roadbed. and of uniform width. The distinction between gullyand rill is one of depth.A natural or constructed waterway. The water upstream from a structure or point on a stream. (To) Grade . Grass . whereas a rill is of lesser depth and would be smoothed by use of ordinary tillage equipment. Head (Hydraulics) . Gradient .The environment in which the life needs of a plant or animal are supplied. characterized by blade-like leaves arranged on the culm or stem in two ranks. and underground. Grading . Gully . slope. rather long. legume. Head loss . filling. The energy. the gate at the entrance to a conduit. thereby preventing further head-cutting or lowering of the channel grade. and lost head. just the velocity required for transportation of the load (of sediment) supplied from the drainage basin. Gully erosion . top of embankment or bottom of excavation. velocity. pressure. rill. top of embankment. The finished surface of a canal bed. 6 12/03 A2 . pit. Inoculant .Hydrologic cycle .An approach to land application in which large volumes of wastewater are applied to the land. directly through catch basins.Generally. Relative terms for expressing internal drainage are: none. storage. Impervious .A device used to dissipate the energy of flowing water.A combination of infiltration and inflow waste water volumes in sewer lines that permits no distinction between the two basic sources which have the same effect of usurping the capacities of sewer systems and other sewerage system facilities. It receives little or no water from springs and no long-continued supply from melting snow or other sources. Synonymous to interception ditch. and other vegetation. interception. medium. The rate of movement is determined by the texture. and transpiration. Intermittent stream . Impact basin . dugout. including the presence of an excess of water. an artificial collection or storage of water.A stream or portion of a stream that flows only in direct response to precipitation. Infiltration/inflow . etc. Intercepted surface runoff . Interception (Hydraulics) . and very rapid. inlets.That portion of runoff that contributes to the runoff pollution that enters receiving water as point discharges from separate storm sewer systems and as general surface runoff. sump.A channel excavated at the top of earth cuts.Not allowing infiltration. as a reservoir. Invert . etc.A soil characteristic determining or describing the maximum rate at which wate can enter the soil under specified conditions. It is dry for a large part of the year.The downward movement of water through the soil profile. ordinarily more than 3 months. either permanent or perched. a catch drain. Generally constructed of concrete in the form of a partially depressed or partially submerged vessel. Interflow . and may utilize baffles to dissipate velocities. rapid. Most legumes require a specific bacteria.A peat carrier impregnated with bacteria which forms a symbiotic relationship enabling legumes to utilize atmospheric nitrogen. Indirect runoff . Impoundment . structure.That portion of rainfall that infiltrates into the soil and moves laterally through the upper soil horizons until intercepted by a stream channel or until it returns to the surface at some point downslope from its point of infiltration. either storm or combined.The circuit of water movement from the atmosphere to the earth and back to the atmosphere through various stages or processes such as precipitation.The lowest point on the inside of a sewer or other conduit. infilrate the surface and percolate through the ssoil pores Infiltration rate . Internal soil drainage .The process by which precipitation is caught and held by foliage. percolation. evaporation.That portion of surface runoff that enters a sewer. at the foot of slopes or at other critical places to intercept surface flow. slow.10 . Interception channel . shrubs. very slow. Often used for “interception loss” or the amount of water evaporated from the precipitation intercepted. and branches of trees. and other characteristics of the soil profile and underlying layers and by the height of the water table. infiltration. Infiltratio-percolation . twigs. runoff. have stipules. Legume .A shallow channel excavation at the outlet end of a diversion with a level section for the purpose of diffusing the diversion outflow. Land capability map . the slope of the channel in feet per foot. Level spreader . and for wildlife. Lime . subdivision regulation. beans. or carbonate of calcium or of calcium and magnesium. Practically all legumes are nitrogen-fixing plants. on the total suitability for use without damage for crops that require regular tillage. and floodplain regulation. including climate. caused by a collapse of the structure from shock or other type of strain and associated with a sudden but temporary increase in the pore-fluid pressure.486r2/3S1/2 n where: V r s n is the mean velocity of flow in feet per second is the hydraulic radius in feet is the slope of the energy gradient or. one of the most important and widely distributed plant families. Leaves are alternate.Lime. for woodland. It involves a temporary transformation of the material into a fluid mass. Liquid limit . The fruit is a “legume” or pod that opens along two sutures when ripe. In engineering. Spontaneous . including such things as zoning. and are usually compound. Liquefaction. Land use controls . Land capability involves consideration of (1) the risks of land damage from erosion and other causes and (2) the difficulties in land use owing to physical land characteristics. refers to only one compound. The flowers are usually papilionaceous (butterfly-like).The suitability of land for use without permanent damage.An equation used to predict the velocity of water flow in an open channel or pipe lines: V = 1. 6 A2 . alfalfas. the term “lime” is commonly used in agriculture to include a great variety of materials which are usually composed of the oxide. a high liquid limit indicates that the soil has a high content of clay and low capacity for supporting loads. and kudzu. The most commonly used forms of agricultural lime are ground limestone (carbonates).Methods for regulating the uses to which a given land area may be put.Land capability . Land capability. hydroxide. including climate. lespedezas. hydrated lime (Hydroxides). prepared by the USDA. classes and subclasses.The sudden large decrease of the shearing resistance of a cohesionless soil. classes.11 12/03 . as ordinarily used in the United States. Manning’s equation (Hydraulics) . marl. clovers. and subclasses according to their capability for intensive use and the treatments required for sustained use. calcium oxide (CaO). for grazing. Includes many valuable food and forage species. for assumed uniform flow. vetches.A member of the legume or pulse family. Soil Conservation Service. Leguminosae. from the strictly chemical standpoint. and is the roughness coefficient or retardance factor of the channel lining. such as the peas. peanuts.A map showing land capability units.A grouping of kinds of soils into special units. Land capability classification . is an expression of the effect of physical land conditions. burnt lime (oxides). sweet clovers. or a soil survey map colored to show land capability classes. and oyster shells. however.The moisture content at which the soil passes from a plastic to a liquid state. Mulch . cross-sectional area of a stream or channel divided by its surface or top width.A natural or artificial layer of plant residue or other materials covering the land surface which conserves moisture. natural watercourses. The C horizon may or may not consist of materials similar to those from which the A and B horizons developed. those substances that promote growth of algae and bacteria. holds soil in place.Pollution that enters a water body from diffuse origins on the watershed and does not result from discernible.A waterway constructed or altered primarily to carry water from man-made structures.12 .Depth of flow in an open conduit during uniform flow for the given conditions.The unconsolidated.A substance necessary for the growth and reproduction of organisms.A pipeline or conduit device. location. or artificial drain. river. lake. more or less chemically weathered mineral or organic matter from which the solum of soils has developed by pedogenic processes. that provides for the discharge or portions of combined sewer flows into receiving waters or other points of disposal.The rate.Soil and water conservation practices that primarily change the surface of the and or that store. convey. Mechanical practices . It is equal to the discharge divided by the cross-sectional areas of the reach. Percolation . etc.Mean depth (Hydraulics) . Natural drainage . Outfall . Outlet channel . after a regular device has allowed the portion of the flow which can be handled by interceptor sewer lines and pumping and treatment facilities to be carried by and to such water pollution control structures. Peak discharge . Percolation test .The movement of water through soil. Nutrient(s) . swales. at which water moves through saturated granular material.The average velocity of a stream flowing in a channel or conduit at a given cross-section or in a given reach. together with an outlet pipe. Percolation rate . Open drain . gullies. In water.A determination of the rate of percolation or seepage of water through natural soils expressed as time in minutes for a 1-inch fall of water in a test hole. Outlet . Overflow .The flow patterns of stormwater runoff over the land in its pre-development state.Natural watercourse or constructed open channel that conveys drainage water.Point of water disposal from a stream. usually expressed as a velocity. Parent material (soils) . or dispose of runoff water without excessive erosion. depressions. or structure where wastewater or drainage discharges from a sewer to a receiving body of water. rills. Elements of natural drainage include overland flow. chiefly nitrates and phosphates. Normal depth . such as terraces. tidewater. Nonpoint source pollution .The maximum instantaneous flow from a given storm condition at a specific location.Average depth. confined or discrete conveyances. regulate. aids in establishing plant cover. and diversions. and minimizes temperature fluctuations.The point. tile lines. 6 12/03 A2 . Mean velocity . A dam spillway generally constructed of permanent material and designed to regulate the normal water level. I is the rainfall intensity and is the area.The moisture content at which a soil changes from a semi-solid to a plastic state.3 to 20.20 inches per hour.Perennial stream .06 inches per hour.A numerical measure of acidity or hydrogen ion activity. and of alkalinity. pH .0. Phosphorus. Retention structure . The permeability of a soil may be limited by the presence of one nearly impermeable horizon even though the others are permeable. Moderately rapid 2. 6 A2 .0.A device used to dissipate the energy of flowing water that may be constructed or made by the action of flowing.0 are alkaline. where C is a coefficient describing the physical drainage area.Allowing movement of water.20 to 0.6. Pervious .0 inches per hour. All pH values below 7.0. Porous pavement . Plasticity index .A pavement through which water can flow at significant rates. Pollution .The numerical difference between the liquid limit and the plastic limit of soil. Moderate . Permeability rates are classified as follows: (a) (b) (c) (d) (e) (f) (g) Very slow .The volume of pore space in a rock.06 to 0.The rate at which water will move through a saturated soil.63 to 2.A natural or artificial basin that functions similar to a detention structure except that it maintains a permanent water supply. These facilities may be protected by various lining materials. Soil .0 to 6. may be temporary or permanent. The neutral point is pH 7.A means of computing storm drainage flow rates (Q) by use of the formula Q = CIA.0. Rational method . Plastic limit . Permeability.Inorganic phosphorus that is readily available for plant growth. Moderately slow . Principal spillway . the range of moisture content within which the soil remains plastic.The presence of a body of water (or soil or air) of substances of such character and in such quantities that the natural quality of the environment is impaired or rendered harmful to health and life or offensive to the senses.63 inches per hour. Very rapid . Permeability rate . provide flood protection and/or reduce the frequency of operation of the emergency spillway.3 inches per hour. Porosity . that will pass through a square foot of porous surface in one day. Available .A stream that maintains water in its channel throughout the year.The volume of water.0 inches per hour.less than 0. Permeability coefficient . Rapid . under a head of one foot.The quality of soil horizon that enables water or air to move through it.0 are acid and all above 7.The storage of stormwater to prevent it from entering the sewer system.13 12/03 . in cubic feet.More than 20. Plunge pool . Slow . Retention .0 inches per hour. or steel.The clearing and digging action of flowing air or water. the point at which a soil or an aquifer will no longer absorb any amount of water without losing an equal amount. Sediment pool .The quantity of sediment. Sediment .The fraction of the soil eroded from upland sources that actually reaches a continuous stream channel or storage reservoir. See Soil Texture. for protection against the action of water (waves). A committee on sedimentation of the National Research Council has established a classification of textural grade sizes for standard use. timber. Scour . Saturation point . Sediment delivery ratio . in open channels or in stormwater conveyance systems. measured in dry weight or by volume.A major water resource region. or other similar materials used for soil erosion control. Sediment discharge consists of both suspended load and bedload. or ice and has come to rest on the earth’s surface either above or below sea level. Runoff .A depression formed from the construction of a barrier or dam built at a suitable location to retain sediment and debris. Settling basin .14 . Riser . such as the face of a dam or the bank of a stream.05 and 0.In soils. transported through a stream cross-section in a given time. usually only a few inches deep. Sediment basin . Sediment discharge . See Drainage Basin. water. or boulders placed on earth surfaces.A small intermittent watercourse with steep sides. brush and stone. A soil textural class.Rill. Riprap . Silt . River basin .That portion of precipitation that flows from a drainage area on the land surface.Solid material. has been divided into 20 major water resource regions (river basins). Sediment grade sizes . 6 12/03 A2 . especially the downward erosion caused by streamwater in sweeping away mud and silt from the outside bank of a curved channel or during a flood.The reservoir space allotted to the accumulation of submerged sediment during the life of the structure.002 millimeter in equivalent diameter.The soil prepared by natural or artificial means to promote the germination of seed and the growth of seedlings. both mineral and organic.S. The U. Rock-fill dam .An enlargement in the channel of a stream to permit the settling of debris carried in suspension.A soil consisting of particles between 0. often with the upstream part constructed of handplaced or derrick-placed rock and faced with rolled earth or with an impervious surface of concrete.A young plant grown from seed.The inlet portions of a drop inlet spillway that extend vertically from the pipe conduit barrel to the water surface. is being transported. Also applied to brush or pole mattresses. or has been moved from its site of origin by air.Broken rock.Measurements of sediment and soil particles that can be separated by screening.A dam composed of loose rock usually dumped in place. gravity. Seedling . cobbles. that is in suspension. Seedbed . See Soil Texture. as 2:1. measured as a numerical ratio. Stream gaging . of a stream channel. Silty clay . some types are crumb structure. or other measuring instruments at selected locations.g. Spillway . approximately parallel to the surface. Soil horizon . that has distinct characteristics produced by soilforming factors. See Gaging station. It may contain gates.. a 5year. See Soil Texture. Expressed as a ratio. Sub-basin . Slope . or both. Soil conservation . Soil structure . Streambanks . and columnar structure. either manually or automatically controlled.Using the soil within the limits of its physical characteristics and protecting it from unalterable limitations of climate and topography.A layer of soil. a lesser quantity of clay.The slope of a channel at which neither erosion or deposition occurs. Storm frequency .The unconsolidated mineral and organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants. Soil texture . 6 A2 . not the flood boundaries. weirs. to regulate the discharge of excess water. percent. the slope is the angle from the horizontal plane.15 12/03 . street wash and other wash waters or drainage. the first number is the horizontal distance (run) and the second is the vertical distance (rise). Silty clay loam .A physical division of a larger basin. Expressed in degrees. Soil profile .A passage such as a paved apron or channel for surplus water over or around a dam or similar obstruction.A sewer that carries stormwater and surface water. Stabilized grade . current meters.A soil textural class containing a relatively large amount of silt and clay and a small amount of sand.A soil textural class containing a large amount of silt and small quantities of sand and clay.The time interval between major storms of predetermined intensity and volumes of runoff e.The relation of particles or groups of particles which impart to the whole soil a characteristic manner of breaking. with a 90o slope being vertical (maximum) and 45o being a 1:1 or 100 percent slope.A vertical section of the soil from the surface through all horizons. An open or closed channel. block structure. or in degrees. associated with one reach of the storm drainage system. Also called a storm drain. A 2:1 slope is a 50 percent slope. Storm sewer .Degree of deviation of a surface from the horizontal. including C horizons.A soil textural class containing a relatively large amount of silt. Soil . platy structure. Right and left banks are named facing downstream. used to convey excess water from a reservoir.The physical structure or character of soil determined by the relative proportions of the soilseparates (sand. 10-year or 20-year storm. and a still smaller quantity of sand.The quantitative determination of stream flow using gages.The usual boundaries. See Soil Texture. but excludes sewage and industrial wastes. silt and clay) of which it is composed.Silt loam . Swales conduct stormwater into primary drainage channels and provide some groundwater recharge. Tile. and other physiographic features. Drain .General term to include characteristics of the ground surface such as plains.Precipitation that falls onto the surface of roofs. Although a common term. Tailwater depth . Swale .A subdivision of a drainage basin (generally determined by topography and pipe network configuration). Surface water . caused by suspended solids. usually having a vegetative cover. Terrace interval .Cloudiness of a liquid. Subwatershed . the subsoil can be defined as the soil below the plowed soil (or its equivalent of surface soil). in short lengths.A pervious backfilled trench containing stone or a pipe for intercepting groundwater or seepage. a measure of the suspended solids in a liquid.Distance measured either vertically or horizontally between corresponding points on two adjacent terraces. Suspended solids . Toe drain . usually laid with open joints to collect and carry excess water from the soil. Terrace outlet channel . Subdrain .Solids either floating or suspended in water.Channel. and is not absorbed or retained by that surface. hills.A series of terraces occupying a slope and discharging runoff into one or more outlet channels. streets. steepness of slopes. it usually heavily vegetated. Terrace system . or similar material.The B horizons of soils with distinct profiles. Tile drainage . degree of relief. ground.An embankment or combination of an embankment and channel across a slope to control erosion by diverting or storing surface runoff instead of permitting it to flow uninterrupted down the slope.A structural device used to prevent debris from entering a spillway or other hydraulic structure. Surface runoff . and is normally without flowing water.The depth of flow immediately downstream from a discharge structure. in which roots normally grow. Topography . into which the flow from one or more terraces is discharged and conveyed from the terrace system. Trash rack . Subsoil .All water.16 .Pipe made of burned clay. Terrace . concrete.Land drainage by means of a series of tile lines laid at a specified depth and grade. Turbidity .A watershed subdivision of unspecified size that forms a convenient natural unit. In soils with weak profile development. it cannot be defined accurately. 6 12/03 A2 . It has been carried over from early days when “soil” was conceived only as the plowed soil and that under it as the “subsoil”. the surface of which is exposed to the atmosphere..Subcatchment .A drainage system constructed in the downstream portion of an earth dam or levee to prevent excessive hydrostatic pressure. mountains. etc. sewage or other liquid wastes.An elongated depression in land surface that is at least seasonally wet. but collects and runs off. physical. Water quality standards . 6 A2 .Stabilization of erosive or sediment-producing areas by covering the soil with: (a) (b) (c) Permanent seeding.The upper surface of the free groundwater in a zone of saturation. A zoning ordinance is one of the major methods for implementation of a comprehensive plan. and use of land for residential. See Drainage Basin. commercial.Surface runoff from an urban drainage area that reaches a stream or other body of water or a sewer. Uniform flow . such as domestic consumption. recreation.Formulation of a plan to use and treat water and land resources. Water control (soil and water conservation) . Watercourse .17 12/03 .Unified soil classification system (engineering) . Urban runoff .Use.The opening in a weir for the passage of water.The region drained by or contributing water to a stream. Regulations generally cover such items as height and bulk of buildings. and treatment of water and land resources of a watershed to accomplish stated objectives. etc. and liquid limit. either continuously or intermittently.A term used to describe the chemical. for example. or other body of water. producing areas covered with a turf of perennial sod-forming grass. producing temporary vegetative cover. Short-term seeding. waste disposal.An ordinance based on the police power of government to protect the public health. Zoning ordinance . Watershed . Water quality . safety. lake. usually in respect to its suitability for a particular purpose. industrial. agricultural. Water classification . pH. navigation. locus of points in soil water at which hydraulic pressure is equal to atmospheric pressure. Watershed management . gradation. Water resources .The supply of groundwater and surface water in a given area. producing long-term vegetative cover. Water table .Separation of water of an area into classes according to usage. Weir notch . density of dwelling units. and biological characteristics of water. industrial. Watershed planning . water for agricultural use in irrigation systems should not exceed specific levels of sodium bicarbonates. regulation.Minimum requirements of purity of water for various uses. or agricultural purposes.All land and water within the confines of a drainage divide or a water problem area consisting in whole or in part of land needing drainage or irrigation. etc.A state of steady flow when the mean velocity and cross-sectional area remain constant in all sections of a reach. and general welfare. Requirements may vary among various geographically defined areas called zones. Vegetative protection .A definite channel with bed and banks within which concentrated water flows. plasticity index. and installation of structures for water retardation and sediment detention (does not refer to legal control or water rights as defined). or Sodding. channel improvement.Device for measuring or regulating the flow of water. Watershed area . It may regulate the type of use and intensity of development of land and structures to the extent necessary for a public purpose. off-street parking. fisheries. control of signs.A classification system based on the identification of soils according to their particle size. Weir .The physical control of water by such measures as conservation practices on the land. total dissolves salts. This page left intentionally blank. 6 12/03 A2 .18 . Appendix A-3 Geotextile Application Guide 6 A3 .1 6/05 . 6 6/05 A3 .This page left intentionally blank.2 . There are two general types of geotextiles under this classification. thus they can generally be considered "drainage type" geotextiles. polyamide. and be mildew and rot resistant. The geotextile shall be inert to commonly encountered chemicals and hydrocarbons. or in a dewatering practice. Geotextile Selection Table for choosing the appropriate type of geotextile for a given situation. dewatering device. subsurface drain. geotextile dewatering bag. polyethylene. They tend to have high tensile strength and low permeability. riprap and gabion mattress chutes. Purpose: To function as a barrier to sediment while allowing water to flow through when used as silt fence. lined channel. such as stone and earth. Type GS geotextiles are used to separate and/or support layers of different media. stabilized construction entrance. geotextiles have been classified into different categories. stream diversion. dependent upon the geotextile application. riprap stilling basin. riprap outlet protection. polyester. pumping pit. This class is further broken down into subclasses depending on the permeability and strength requirements for the given application. dewatering basin. Conditions Where Practice Applies Standard. inlet protection.STANDARD AND SPECIFICATIONS FOR GEOTEXTILE Definition: Woven or non-woven fabric consisting of long chain polymeric filaments or yarns of polypropylene. temporary crossing. reinforced and super silt fence. See Figure A-3b.3 6/05 . the "Type GS" and the "Type GD". Refer to Figure A-3a. Design Criteria For the purposes of this Handbook. or "Types". or polyvinylidene chloride. To provide a stabilized base for stone and riprap applications when used as an underlay. The minimum acceptable values have been established using the ASTM Test Methods listed below: Property Test Method Grab Tensile Strength Grab Tensile Elongation Trapezoidal Tear Strength Mullen Burst Strength Puncture Strength Apparent Opening Size Ultraviolet Stability (% Strength Retained) Flow-thru Rate ASTM D 4632 ASTM D 4632 ASTM D 4533 ASTM D 3786 ASTM D 4833 ASTM D 4751 ASTM D 4355 ASTM D 4491 6 A3 . Type GD geotextiles are used in applications that depend on the passage of water through the fabric. Geotextile Properties Table for the minimum acceptable property values for the various geotextile types and applications. culvert inlet protection. storm drain inlet protection. “Use Type GD-II geotextile. on the pumping pit detail.The designer shall specify on the plan the “Type” of geotextile for the application. such as “Type GD-II geotextile” for use in a pumping pit. Geotextile Properties Table for the minimum acceptable values for Type GD-II geotextile in selecting an alternate product. In addition.Type 2 Gabion Chute Lined Channel Riprap Chute Riprap Outlet Protection Riprap Stilling Basin Stabilized Construction Entrance Stream Diversion Temporary Crossing Mirafi 600X Amoco 2006 Geotex 315ST GD-I Culvert Inlet Protection Reinforced Silt Fence Silt Fence Super Silt Fence Mirafi 100X Geotex 915SC Amoco ProPex 2130 GD-II Dewatering Basin . the contractor wishes to substitute a product. “or approved equal”. Geotextile products may also be used in stormwater management facilities.4 . The designer shall determine the appropriate geotextile to be used in stormwater management applications. If the contractor wishes to substitute products.Type 2 Silt Sack High Flow Dandy Bag II Ultra-Drain Guard GD-IV Geotextile Dewatering Bag Dirtbag 53/55 Dandy Dewatering Bag TerraTex N08/N10 Figure A-3a Geotextile selection table 6 6/05 A3 . If. during construction. a note would be included that says. such as infiltration trenches and bioretention facilities. he/she should refer to Figure A3b. and listing of a product is not an endorsement of its use. to be used for that application.Type 1 Pumping Pit Mirafi FW402 GeoTex 111F Amoco 4535 GD-III Inlet Protection .Type 1 Dewatering Device Inlet Protection . It is the responsibility of the designer to specify a product that meets all of the site criteria. a specific product. it must be with the concurrence of the designer and plan approval agency. The example products cited in this appendix do not represent a complete list of all products. Considerations The information in this geotextile reference section is generally intended for use with respect to the standard erosion and sediment controls presented in this Handbook. “or approved equivalent” shall be included on the plan. Mirafi FW402 or approved equivalent”. and specify on the plan a manufacturer’s product. To further this example. All substitutions must have prior approval from the appropriate plan approval agency. Geotextile Selection Table Type Application Example Products GS-I Separation / Stabilization / Underlayment for: Dewatering Basin . 5 6/05 .Geotextile Properties Table Type GS-I GD-I GD-II GD-III GD-IV Minimum Grab Tensile Strength (ASTM D-4632) 315 lbs 110 lbs 80 lbs 265 lbs 200 lbs Maximum Grab Tensile Elongation (ASTM D-4632) 15% 20% 50% 20% 50% Minimum Trapezoidal Tear Strength (ASTM D-4533) 120 lbs 50 lbs 35 lbs 45 lbs 80 lbs Minimum Mullen Burst Strength (ASTM D-3786) 600 psi 300 psi 160 psi 420 psi 380 psi Minimum Puncture Strength (ASTM D-4833) 120 lbs 60 lbs 45 lbs 100 lbs 130 lbs Apparent Opening Size (ASTM D-4751) 40-80 US Sieve 40-80 US Sieve 40-80 US Sieve 20-40 US Sieve 40-80 US Sieve Minimum UV Resistance after 500 hours (ASTM D-4355) 70% 70% 70% 70% 70% Flow-thru Rate (ASTM D-4491) 5 gal/min/sqft maximum 25 gal/min/sqft 110 gal/min/sqft 110 gal/min/sqft 70 gal/min/sqft maximum minimum minimum minimum Figure A-3b Geotextile properties table 6 A3 . This page left intentionally blank.6 . 6 6/05 A3 . 1 12/03 .Appendix A-4 Stabilization Matting Application Guide 6 A4 . 6 12/03 A4 .This page left inentionally blank.2 . Example Products: North American Green C125.55 psf. where natural vegetation will provide permanent stabilization. it must be with the concurrence of the designer and plan approval agency. Stabilization matting is divided into two categories: temporary matting described as soil stabilization matting.8 lbs/SY. It is also composed of 100% agricultural straw (min 0.6. Landlok TRM 1060. North American Green S75. It is composed of 70% agricultural straw or wood excelsior fiber and 30% coconut (coir) fibers with two plastic or woven biodegradable nettings with UV stabilization on the top side.80 psf.0 psf.or bio-degradable material.5 lbs/SY) or 100% wood excelsior fiber (min 0. either a temporary soil stabilization mat or a permanent turf reinforcement mat.) should be noted on the plan along with a manufacturer’s product (i. where natural vegetation will provide permanent stabilization.8 lbs/SY. during construction. but it contains a double netting (top and bottom) of either photo. The matting type from this manual (i. and permanent matting described as turf reinforcement matting.3 12/03 . etc. the contractor wishes to substitute a product. Example Products: North American Green SC150. Synthetic Industries Landlok CS2. min 80% six-inch or longer fiber length) with a single top netting of either photo.65 psf. Synthetic Industries Landlok S2. 6 A4 . It is composed of 100% agricultural straw (min 0. An SSM-II is acceptable on slopes of 2:1 or flatter and in low flow swales with a maximum design shear stress of 1.). SSM-II is also a temporary mat that will degrade within 12 months. An SSM-I is acceptable on slopes of 3:1 or flatter and in low flow swales with a maximum design shear stress of 1. It is the responsibility of the designer to specify a product that meets all of the site criteria. Soil Stabilization Matting Types I through IV (SSM-I through SSM-IV) are temporary to long-term degradable mattings. SSM-IV is a long term mat lasting 24 to 36 months. PPS Packaging Xcel Straw Regular SR1. Example Products: North American Green S150.5:1 or flatter and in medium flow swales with a maximum design shear stress of 1. uses.4. They can be used both in slope applications and as temporary channel liners. Synthetic Industries Landlok S1. American Excelsior Curlex I. American Excelsior Curlex II.e. An SSM-III is acceptable on slopes of 1.5 lbs/SY) or 100% wood excelsior fiber (min 0. SSM-I is a temporary mat that will degrade within 12 months. SSM-I.BACKGROUND Section 3. Example Products: North American Green S75. etc. min 80% six-inch or longer fiber length). A brief description of each category and each type of matting follows. where natural vegetation will provide permanent stabilization.or bio-degradable material. and benefits of stabilization matting. where natural vegetation will provide permanent stabilization. This appendix will aid the designer in specifying the appropriate matting on the sediment and stormwater plan. and listing of a product is not an endorsement of its use. Slopes of 3:1 or steeper and all areas of concentrated flow will require some form of stabilization matting. The example products cited in this appendix do not represent a complete list of all products. It is composed of 100% coconut (coir) fibers or 100% polypropylene fibers with two plastic or woven biodegradable nettings with UV stabilization. An SSM-IV is acceptable on slopes of 1:1 or flatter and in high flow swales with a maximum design shear stress of 2. Standard and Specifications for Stabilization Matting discusses the general composition. SSM-III is an extended term mat lasting 12 to 24 months. TRM-II. Synthetic Industries Landlok C2. If. applied to the soil surface to prevent erosion prior to vegetative establishment.e. TRMs can be used both in slope applications and as permanent channel liners. Products in the TRM-IV category have a maximum tensile strength in the machine direction of 1. Products in the TRM-III category have a maximum tensile strength in the machine direction of less than 1. TRM-IV may be specified for use in stormwater management pond emergency spillways in lieu of riprap (up to a riprap size of R4) where infrequent flow will occur and grass is preferred over riprap. North American Green P300 and Contech C-45 (all non-vegetated).500 lbs or greater. 1060 and 1061B (all vegetated). Example Products: Landlok TRM 450. 6 12/03 A4 . and Colbond Enkamat 7010 and 7020 (vegetated). TRM-IV is not applicable as a replacement for riprap in areas of outlet protection where concentrated flow is anticipated. TRM-I provides permanent soil and turf reinforcement on slopes steeper than 1:1 and in channels where maximum design shear stress over a 50-hour flow duration is 2 psf or less and where natural vegetation alone will not provide long term stabilization. Example Products: Pyramat High Performance TRM and Colbond Enkamat S-20 (all vegetated). depending upon the site conditions and desired results.4 . TRM-IV provides permanent soil and turf reinforcement on slopes steeper than 1:1 and in channels where the maximum design shear stress over a 50-hour duration of flow ranges from 6 psf to 8 psf and where natural vegetation alone will not provide long term stabilization. TRM-II provides permanent soil and turf reinforcement on slopes steeper than 1:1 and in channels where maximum design shear stress over a 50-hour flow duration ranges from 2.Turf Reinforcement Mats Types I through IV (TRM-I through TRM-IV) are permanent. non-degradable three-dimensional mattings that provide a matrix for the roots of vegetation to penetrate and entangle. Example Products: North American Green P550 (non-vegetated). Landlok TRM 450. Example Products: North American Green P300 and P550 (vegetated). TRM-III provides permanent soil and turf reinforcement on slopes steeper than 1:1 and in channels where maximum design shear stress over a 50-hour flow duration ranges from 6 psf to 8 psf and where natural vegetation alone will not provide long term stabilization. Pyramat High Performance TRM (non-vegetated).9 psf and where natural vegetation alone will not provide long term stabilization. Some TRMs offer the option of being soil-filled or non-soil-filled. Mirafi Miramat TM8 (vegetated).500 lbs. and Contech C-60 (vegetated).1 psf to 5. North American Green S150. 5. the criteria are based upon the slope’s steepness. Determine the proposed application of the mat. either to stabilize a slope or to line a channel. a temporary channel lining may be used. 2. If the product fits the site. b. non-erosive channel. 3:1 – 2:1) capture all slopes between those values. the criteria are based upon the calculated shear stress for the channel. The stabilization matting type from the reference table is the most appropriate for the application. the plan must clearly delineate the locations where each type will be applied. Select the appropriate criteria classification depending upon the application. but is considered a minimum.e. Stabilization Matting Selection Table The Stabilization Matting Selection Table is a quick reference to be used as a starting point when specifying stabilization matting for a site. Shear stress shall be calculated using Design Guide DG-1. If HEC-15 results show that reinforcement beyond grass is necessary to produce a stable. Specify the matting type (i. The criteria ranges in Figure A-4a correspond directly with the matting type. For slope applications. When more than one type stabilization matting will be used on the same site. Ranges for slope steepness (i.e. a permanent channel lining will be necessary. If a single matting type can be used. If HEC-15 results show that the channel will be stable once vegetation is established. as long as it does not inhibit vegetative growth.5 12/03 . A matting that is rated for more extreme conditions may be used for less intense applications. that may be preferable to avoid confusion during construction. For channel lining applications. FHWA HEC-15 Design of Flexible Channel Linings. to the full length of the slope”. To use the table. 6 A4 . provide notation on the plan such as “apply SSM-II. Choose a product that meets the criteria for that type of matting from the descriptions in this document above (i. SSMII) for each separate application on the plan. The designer should consider this when specifying several matting types for a site. a. follow these steps: 1. 3. Shear stress minimums and ranges are provided in the table. 4.Use of Figure A-4a. 100% agricultural straw with double netting) then refer to the manufacturer’s specifications for that product to verify its applicability to the proposed site conditions.e. 5:1 or flatter SSM-III North American Green SC150 Synthetic Industries Landlok CS2 1:1 or flatter SSM-IV North American Green C125 Synthetic Industries Landlok C2 steeper than 1:1 TRM-I Landlok TRM 450 (non-vegetated) North American Green P300 (non-vegetated) Contech C-45 (non-vegetated) < 1.80 psf SSM-III North American Green SC150 Synthetic Industries Landlok CS2 < 2.8 psf and <1500 lbs min tensile strength (Machine Direction) TRM-III North American Green P550 (vegetated) Colbond Enkamat 7010 (vegetated) 6 psf .65 psf SSM-II North American Green S150 American Excelsior Curlex II < 1.8 psf and >1500 lbs min tensile strength (Machine Direction) TRM-IV Pyramat High Performance TRM (vegetated) Colbond Enkamat S-20 (vegetated) Figure A-4a Stabilization matting selection table 6 12/03 A4 .1 psf .9 psf TRM-II Mirafi Miramat TM8 (vegetated) Landlok TRM 1060 & 1061B (vegetated) Contech C-60 (vegetated) 6 psf .6 .5.Stabilization Matting Selection Table Application Slope Stabilization Channel Lining.0 psf SSM-IV North American Green C125 Synthetic Industries Landlok C2 < 2 psf TRM-I Landlok TRM 450 (non-vegetated) North American Green P300 (non-vegetated) Contech C-45 (non-vegetated) 2. Temporary Channel Lining. Permanent Criteria Type Example Products 3:1 or flatter SSM-I North American Green S75 American Excelsior Curlex I PPS Packaging Xcel Straw Regular SR1 2:1 or flatter SSM-II North American Green S150 Synthetic Industries Landlok S2 1.55 psf SSM-I Synthetic Industries Landlok S1 American Excelsior Curlex I < 1. 1 12/03 .Appendix A-5 Riprap & Stone Properties Tables 6 A5 . 2 . 6 12/03 A5 .This page left intentionally blank. R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 Graded Rock Size (in) d50** Min. Max.RIPRAP PROPERTIES NSA* No. should be larger than this size Figure A5a Riprap properties table 6 A5 . 8 3 1. 1. Blanket Thickness (in) 3 5 9 18 22 29 36 58 * National Stone Association ** 50% of pieces.5 1 6 3 2 12 6 3 18 9 5 24 12 7 30 15 12 48 24 15 Min.5 0. by weight.3 12/03 .75 No. Figure A5b Crushed stone properties table 6 12/03 A5 .15 0-5 100 95 .5) (9.4 d50 (in) 2.5) (4.375 0. inches (mm) CRUSHED STONE PROPERTIES 0-5 0-5 0-5 0 . 1 2 3 57 67 8 10 Sieve Size (square openings). 100 (1.70 0 .15 0-5 100 90 .55 0 . 16 No.5 2 1.1875 4" 3-1/2" 3" 2-1/2" 2" 1-1/2" 1" 3/4" 1/2" 3/8" No.15 0-5 100 90 .100 20 .10 100 90 .Section 813 DE No.DelDOT Standard Specifications .10 100 85 .375 0.100 25 . 8 (2.10 10 .100 Source .5) (25) (19) (12.60 0 .5 0.100 25 .100 35 .August 2001 .30 No.75) 100 90 .60 0 .18) (150 um) No.5 0.30 100 85 .100 10 .70 0 . 4 (100) (90) (75) (63) (50) (37.36) .100 35 . Design Guide DG-1 FHWA HEC-15 Design of Roadside Channels With Flexible Linings 6 DG1 - 1 12/03 This page left intentionally blank. 6 12/03 DG1 - 2 - - I FOREWORD This ImplementationPackageprovides guidancefor the design of stableconveyancechannelsusingflexible linings. The information in the manualshouldbe of interest to State and Federal Hydraulics engineersand others responsiblefor stabilizing roadsidechannels. The manual has been adoptedas HEC-15 in the HydraulicsEngineeringCircular Series. Copiesof the manualare beingdistributedto FHWA regionalanddivision offices and to eachState highway agencyfor their use. Additional copiesof the report canbe obtainedfrom the National TechnicalInformation Service,5280Port Royal Road,Springfield, Virginia 22161. StanleyR. Byington, Director Office of Implementation NOTICE This document is disseminatedunder the sponsorshipof the Department of Transportation in the interest of information exchange. The United States Governmentassumesno liability for the contentsor the usethereof. The contents of this report reflect the views of the author, who is responsible for the facts and the accuracyof the datapresentedherein. The contentsdo not necessarilyreflect the policy of the Departmentof Transportation. This report does not constitute a standard, specification, or regulation. The United StatesGovernmentdoesnot endorseproductsor manufacturers. Trade or manufacturers’namesappearherein only becausethey are consideredessentialto the objectiveof this document. Technical 1. Report 2. No. FHWA-IP-87-7 HEC #15 4. Title and of Roadside Channels Y. H. Chen and Mr. Performing Organization Sponsoring Agency s upplementory Project Technical 16. Recipient’s 5. Report Catalog NO. with Flexible Date April Linings Name ond 1988 6. Performing Organization Code 8. Performing Organization Report No. G. K. Cotton Name and 10. Address Work Un,t No. (TRAIS) 35ZH078 Inc. 11. 80522 Contract or Grant No. .DTFH61-84-C 00055 13. and Type of Report ' Final Report September 1984 Address Office of Implementation, HRT-10 Federal Highway Administration 6300 Georgetown Pike . . . Mclean, Vir;inla 77101 15. 3. Page I Simons, 'Li & Associates, 3555 Stanford Road P.O. Box 1816 Fort Collins, Colorado 12. No. Documentation Author’s) Dr. 9. Accession Subtitle Design 7. Government deport 14. Sponsoring Agency Period Covered - March 1986 Code Notes Managers: John M. Kurdziel, Thomas Assistants: Philip L: Thompson, Krylowski Dennis L. J. Sterling Richards, Jones Abstract Flexible linings provide a means of stabilizing roadside channels. Flexible linings are able to conform to changes in channel shape while maintaining the overall lining integrity. Permanent flexible lining such as riprap, gravel, or vegetation reinforced with synthetic mat are suitable for hydraulic conditions similar to those requiring rigid linings. Vegetation or temporary linings are suited to hydraulic condition where uniform flow exists and shear stresses are moderate. Design procedures are given for rock riprap, wire-enclosed riprap, gravel riprap, woven paper net, jute net, fiberglass roving, curled wood mat, synthetic mat, and straw with net. Special design procedures are presented for composite channels and channels with steep gradients. The design procedures are based on the concept of maximum permissible tracMethods for determination of hydraulic resistance and pertive force. missible shear stress for individual linings are presented. Nomographs are provided for solution of uniform flow conditions in trapezoidal channels. Nomographs are also provided for determination of resistance characteristics for vegetation and permissible shear stress for soils. 17. Key Words 18. channel lining, channel stabilization, tractive force, resistance,permissible shear stress, vegetation,' riprap, jute, fiberglass roving, excelsior, synthetic mat, woven paper net 19. Security Clossif. (of this report) 20. Form DOT F 1700.7 Statement document is available to through the National Technical Information Springfield, Virginia 22161 Security Unclassified Distribution This Classif. (of this page) Unclassified N-72) Reproduction of completed 21. No. 124 page authorized of Pages the public Service, 22. Price Memorandu Pw USDepartment of Transportation Federal Highway Administration Subject: ! in ft Yd mi From: To: inI ft* yd* ml2 ac 6300 Georgetown McLean, Virginia Pike 22101-2296 SYFb in II I Implementation Package."Design of Roadside Channels with Flexible Linings" Report No, FHWA-IP-87-7 Director, Director, Office Office of of Implementation Engineering Date on20 ft 1988 yd mi Reply to Attn. of: HRT-10 in* ft2 mi* ac Regional Federal Highway Administrators Direct Federal Program Administrator This manual addresses the design of stable conveyance channels using flexible linings. These linings are able to conform to changes in channel shape while maintaining the overall lining integrity. Permanent flexible linings such as riprap, gravel or vegetation reinforced with synthetic mat are suitable for hydraulic conditions similar to those requiring rigid linings. Vegetation or temporary linings are suited to hydraulic conditions where uniform flow exists and shear stresses are moderate. Design procedures are given for rock riprap, wire-enclosed riprap gravel riprap, woven paper net, jute net, fiberglass roving, curled wood'mat synthetic mat and straw. Special design procedures are presented for' composite channels and channels with steep gradients. The design procedures are based on the concept of maximum permissible tractive force. Nomographs are provided. 02 lb T fl Direct distribution of the report is being made to Region and Division Offices. If you have any questions concerning the report or require additional copies, please contact Mr. Thomas Krylowski at (FTS) 285-2359, c NO Fahrenheit ~~~at,-mperature l : - S, ie the eymbol for the International system of Meas”rements 02 lb T s fl 02 gal ft’ s yd' TABLE OF CONTENTS Page I. II. INTRODUCTION BACKGROUND ............... Lining Types Performance Characteristics Information on Flexible III. 1 ........................... ; Linings .......... .................. ................ DESIGN CONCEPTS 10 12 ................... Open-Channel Flow Concepts ................. Stable Channel Design Concepts ...................... Design Parameters IV. STEEP GRADIENT COMPOSITE LINING 16 17 17 ........................ :: 19 ............ ;z 22 CHANNEL DESIGN ...................... Steep Slope Design Other Considerations for Steep Slope ....................... Design Procedures ........................ Example Problems VI. 15 DESIGN PROCEDURE ..................... Flexible Lining Design .................... Permissible Shear Stress Determination of Normal Flow Depth Determination of Shear Stress on ChanAei ...................... Side Slope Stability ................... Maximum Discharge Approach Design Considerations for Riprap Lining ....................... Design Procedures ....................... Example Problems V. 3 4 5 Design .......... 52 52 53 54 DESIGN ..................... Special Considerations ........................ Design Procedure ....................... Example Problem 69 70 71 iii TABLE OF CONTENTS (continued) APPENDIX A EQUATIONS FOR VARIOUS CHANNEL GEOMETRIES APPENDIX B DEVELOPMENT OF DESIGN CHARTS AND PROCEDURES APPENDIX C DEVELOPMENT OF STEEP GRADIENT DESIGN CHARTS AND PROCEDURES . . . . . . . . . . . . . . . . . . APPENDIX D SUGGESTED GUIDELINE SPECIFICATIONS GLOSSARY................ REFERENCES . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iV LIST OF FIGURES Page Figure 1. Rigid Concrete Channel Figure 2. Composite Figure 3. Vegetative Figure 4. Riprap Figure 5. Wire Figure 6. Gravel Figure 7. Woven Paper Figure 8. Installed Figure 9. Jute Net Lining Figure 10. Installed Figure 11. Fiberglass Roving Figure 12. Installation of Figure 13. Curled Figure 14. Installed Curled Figure 15. Synthetic Mat Lining Figure 16. Installed Synthetic Figure 17. Straw Figure 18. Typical Figure 19. Shear Figure 20. Location Figure 21. Worksheet Figure 22. Gradations Figure 23. Worksheet Channel Lining Channel Channel Riprap Channel Lining Net (Riprap 6 .................. 6 .................. 6 ............. Lining Net 7 ............ Lining 7 7 ............ Lining 7 ................ Lining Fiberglass Roving 8 Along ... a Roadside ................. Lining ........ Lining 8 ................. Mat Channel Channel Distribution Lining of Shear Distribution Sketch of for Example in Flexible of Granular Flexible 9 ......... Lining 9 .......... Stress a Channel 14 Bend for ....... Example 14 5 .... ......... 4 and 5 Filter Blanket Lining Design .......... V 9 .............. Linings Problems 8 8 Wood Mat Channel Net for 5 ..................... Wood Mat Stress ..... 6 Jute Net Channel With Jute Net) and .................. Channel Woven Paper 4 ................ Lining Lining Enclosed .............. Lining for Example 28 30 8 ... 33 34 LIST OF FIGURES (continued) Page Figure 24. Worksheet for Example Figure 25. Worksheet for Steep Figure 26. Compound Lining Figure 27. Worksheet for Compound Figure 28. Worksheet for Example Problem 13 ........... Figure 29. Equations for Various Channel Geometries ....... Figure 29. Equations for Various Channel Geometries (continued) . 78 Figure 30. Manning's n Versus Relative Roughness for Selected Lining Types . . . . . . . . . . . . . . . . . . . . . 81 . . . . . 86 . . . . . . . . . . . . . 88 Figure 31. Hydraulic Figure 32. Steep Slope Example Forces Slope Problems Design Acting 11 and Channel 12 ....... Design 57 ....... 58 ............... Lining Design on a Riprap Procedure vi 71 ......... Element 74 75 77 LIST OF CHARTS Page Chart 1. Permissible shear stress for noncohesive Chart 2. Permissible shear stress for cohesive Chart 3. Solution various Chart 4. Geometr Chart 5. Chart Chart Chart Chart 6. 7. 8. 9. for side i c design 39 equation for channels of . .'. . . . . , . . . . . . . . . . . 40 41 Manning s n versus class A vegetation for hydraulic radius, R, . . . . . . . . . . . . . . . . . . . 42 Manning I s n versus class B vegetation hydraulic radius, R, for . . . . . . . . . . . . . . . . . . . 43 Manning's n versus class C vegetation for hydraulic radius, R, . . . . . . . . . . . . . . . . . . . 44 Manning's n versus class D vegetation for hydraulic radius, R, . . . . . . . . . . . . . . . . . . . 45 Manning's n versus class E vegetation hydraulic radius, R, for . . . . . . . . . . . . . . . . . . . 46 10. Kb factor Chart 11. Protection Chart 12. Angle shape 13. . . . . , . . Channel ratio,Kl for chart maximum 47 bend . . . 48 of riprap in terms of mean size and . . . . . . . . . . . . . . . . . . . . . . 49 shear stress to bottom shear stress . . . . . . . . . . . . . . . . . . . . . . . . 50 force shear Lp, ratio, stress channels . . . repose stone side trapezoidal bends length, of of for soils . . . . . .,. 38 . . . . . Chart Chart Manning's slopes- soils on channel downstream Chart 14. Tractive Kp Chart 15. Steep slope riprap design, Chart 16. Steep slope riprap design - B = Chart 17. Steep slope riprap design - B = Chart 18. Steep slope riprap design - B = Chart 19. Steep slope gabion mattress, of channel . . . . . . . . . . . . . . . . 51 trapezoidal . . 60 3 . . . . . . . . . 61 3 . . . . . . . . . 62 3 . . . . . . . . . 63 2, z = 4, z = 6, Z = channel tr iangu larchannel,Z=3.. vii Z = 3 64 LIST OF CHARTS (continued) Pase Chart 20. Steep slope gabion mattress, B = 2, Z = 3 . . . . . . . . 65 Chart 21. Steep slope gabion mattress, B = 4, Z = 3 . . . . . . . . 66 Chart 22. Steep slope gabion mattress, B = 6, Z = 3 . . . . . . . . 67 Chart 23. Permissible rock fill shear stress for gabion mattress versus size . . . . . . . . . . . . . . . . . . . . . . 68 Chart Chart 24. 25. Permissible shear mattress thickness Roughness factor stress for gabion mattress versus . . . . . . . . . . . . . . . . . . . . for compound viii channel linings . . . . . . 68 76 LIST OF TABLES Page Table 1. Classification Retardance of Vegetal Covers as to Degree of . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 . . . . . . . . . . . . 37 for Selected Side Slopes and Depth Ratios . . . . . . . . . . . . . . . . . 59 Table 2. Permissible Table 3. Manning's Roughness Table 4. Values of to Bottom A3/Az Width Coefficients Table 5. Empirical Table 6. Relative 35 Shear Stresses Roughness for Lining Coefficients for Resistance Parameters for ix Materials Equation Vegetation . . . . . 80 . . . . . . 80 stress to gravitationa m/set*. superelevation direction Kc = Compound P ft. g = Gravitational L channel. resistance P = Wetted perimeter of flow PR = Wetted perimeter of low-flow of channel. flow ft/sec*. of fabric pores force. is finer by weight. 85 percent. cm. ft. channel. Newton l m*. X 1 force m. of which 50 percent. due to h = Average ratio a r m. Particle size D85 = of the mixture d= prism. or uniform number. cm. ft. flow .LIST OF SYMBOLS A= Cross-sectional area of flow AOS = Measure of the largest sents opening size for than that diameter. in bend to maximum factor. downstream ft. ft. of ft. height = Ratio of upstream of lining KS repreare small m. m. coefficient. ft. of channel kS ft. flow in a bend. shear to bottom shear stress. B= Bottom width CG = Channel D50' of d = Depth of Change in normal Fd = Drag force in in channel. prism. of maximum shear from bend. m. shear stress in I a . geometry. K1 = Ratio of 1 forces inertia acceleration. etc. Kb effective opening which 95 percent trapezoidal depth of = Lift m2. ratio bend. ft. at lb from l bottom ft*. flow. m. Fr = Froude system. flow dn = Depth F1 ft*. vegetation. channel side K2 = Tractive force = Protected length = Roughness height. = Tractive ME1 = Stiffness n = Manning's force factor. of gradation. ratio. in a geotextile. m. ft. m. velocity. channel = Energy ft. vector coarse. cotangent of of channel. m/set. of the distribution of roughness m. lb. = Mean of element. of REG = Roughness Sf rate. of element. Unit III. radius SF = Safety SSF = Side the V* = axis lengths Z= ft. the the plane plane degrees. of ft. P. short slope = Weight “S center factor. = Mean value of the distribution median axes of a roughness y50 line. channel element S = Average ft3/sec. lb/ft3.C. riprap Side slope.P. R = Moment arms a = Angle of m/set. weight weight average measured (3 = Angles between side slope. Hydraulic R= Rc= Mean radius. angle the vector and the Y= water. ft/sec. 6 = Angle side 8 = Angle of between slope. slope. T = Channel V = Mean m. %O m3/sec. factor. flow Q = Discharge. ft/sec. A/P. top width. riprap channel bed Kg.T. Kg/m3. of the repose Q = Stability number. = Point on tangent. gradient. geometry. z = cot $. II’ = Stability number drag of for of from the long and horizontal. xi resultant in in material. gradient. of of the the . side and resultant noncohesive slopes. channel Shear velocity. element. = Point on curve. on sides of slope (bank) Kg/m2.0 = Bed material T = Average gradation. . lb/ft2. maximum depth. lb/ft2. measured xii from lb/ft2. = Shear stress in a bend. Kg/m2. Kg/m'. channel. horizontal. shear stress. lb/ft2. Kg/m2. T d = Shear stress in channel at 'b =P % = Permissible = Shear 4 = Angle shear stress of side stress. Kg/m2. lb/ft2. The vegetation will then provide permanent erosion control in the channel. The primary reference for the design of rigid channels is Hydraulic Design Series No. this manual are deemed flexible linings.(z) 1 . 14. the gradient of the channel typically parallels the grade of the highway. flexible linings may provide only temporary protection against erosion while allowing vegetation to be established. if properly designed.lso provide a buffering effect for runoff contaminants. Rigid linings can be disrupted by these forces whereas flexible linings. As a result. fauna. Damage to a lining is often from secondary forces such as frost heave or slumping. A rigid channel can provide a much higher capacity and in some cases may be the only alternative. the design of energy dissipators and grade-control structures can be found in Hydraulic Engineering Circular (HEC) No. the channel geometry (both in cross section and profile) required for channel stability may not fit within the acquired right-of-way. of Roadside Drainage Channels': (1) For channels which require 3. Hydraulic conditions in the conveyance channel can become severe even at fairly mild highway grades. will retain erosion-control capabilities. flow conditions in chantion.S. DEPARTMENTOF TRANSPORTATION FEDERAL HIGHWAYADMINISTRATION DESIGN OF ROADSIDE CHANNELSWITH FLEXIBLE I. LININGS INTRODUCTION This manual addresses the design of stable conveyance channels using flexible linings. The presence of vegetation in a channel can a. Hydraulically. Design procedures covered in this manual relate to flexible channel linings. Because the roadside channel is included within the highway right-of-way. these channels often require The channel stabilization measures included in stabilization against erosion. "Design other protection measures. nels with flexible linings generally conform to those found in natural chanand thus provide better habitat opportunities for local flora and nels. Flexible linings also have several other advantages compared to rigid They are generally less expensive. Rigid linings tend to fail when a portion of the lining is damaged. Flexible linings are able to conform to change in channel shape while rigid linings can not. The primary difference between rigid and flexible channel linings from an erosion-control standpoint is their response to changing channel shape. Flexible linings have the disadvantage of being limited in the magnitude of erosive force they can sustain without damage to either the channel or the lining.U. Because of this limitation. permit infiltration and exfiltralinings. The result is that flexible linings can sustain some change in channel shape while maintaining the overall integrity of the channel lining. and have a natural appearance. Rigid linings are discussed only briefly so that the reader remains familiar with the full range of channel lining alternatives. In some cases. Riprap design procedures covered in this manual are for channels having a design discharge of 50 cfs or less. the procedure should be checked against the performance of installe channels in the field. The riprap procedure for steep channels is based on an analysis of force acting on the riprap. 2 - . The steep slope design procedure is limited to channel having a design discharge of 50 cfs of less. The current values are based on research conducted at Colorado State University which takes into account the stiffness of the vegetation. th results should be used with caution and be taken as guidance. 11 is recommended for the design of riprap revetments or linings on channels and streams with design flows in excess of 50 cfs. While this procedure is theoretically sound.@ The permissible tractive force and Manning n values provided in thjs manual for grass lined channels cannot be compared to values found in earlier manuals. The use of the procedures in Hydraul-c Engineering Circular (HEC) No. Whenever pos sible. BACKGROUND and research have been done on rigid and Considerable development to the late 1960's. it is useful to classify these materials based characteristics. variety of manufactured and synthetic channel linings applicable to both perRelatively manent and temporary channel stabilization have been introduced. Pr ior Typical materials included rock ze channels. concrete. predominantly used to stabili Since that time a wide stone masonry. and vegetation. or linings are further are classified as . paper.II. Flexible flexible. natural materials were flex i ble channel linings. or synthetic Synthetic mat Fiberglass roving net 3 materials currently on their performance such as concrete. little data on hydraulic performances of these materials are available comWork is continuing on comparing pared to the variety of materials produced. such as vegetation or rock riprap. follows: Rigid Linings Cast-in-place concrete Cast-in-place asphaltic Stone masonry Soil cement Fabric formwork systems Grouted riprap Flexible concrete for concrete Linings Permanent Riprap Wire-enclosed Vegetation Gravel riprap lining Temporary Bare soil Straw with net Curled wood mat Jute. hydraulic performances. Lining materials classified as temporary or permanent. and new material development. material improvement. Lining types are classified as rigid. riprap. Lining Types Because of the large number of channel stabilization available. thaw and swelling soils exert upward forces against the lining and the cycli nature of these conditions can eventually cause failure. Freeze are freeze-thaw. As ricated linings not excessive. they may require protection of underlying to prevent washout. . Side slop instability can develop from excessively high pore pressures and hig hydraulic gradients along the slope surface. Since rigid linings are nonerodible. For example. the cost of rigid channel linings is high. Rigid linings (figure 1) are useful in flow zones wh re high shear stress or nonuniform flow conditions exist. Rigid Concrete Channel Lining. of rigid linings requires specialized equipment and cost1 Prefab a result. they provide an meable lining. Despite the non-erodible nature of rigid linings. soi . such as at transiti IS in channel shape or at an energy dissipation structure. flexible linings are permeable. Excessive soil por pressure occurs when the flow levels in the channel drop quickly. tible to failure from structural instability. i Construction materials. swelling.s nof water or seepage from the channel is undesirable. Riprap and vegetation are suitable linings hydraulic conditions similar to those requiring rigid linings. Once a rigid lining deteriorates. broken slabs are easily moved because the large. This may be necessary if right-of-way limitations restrict the ?1 size.Performance Characteristics Rigid Linings. the designer can use ‘Y channel shape that adequately conveys the flow and provides adequate !board. E The major causes of structural instability and failure of rigid linings and excessive soil pore water pressures. masonry linings often break up and deteriorate if poor. In areas where 1 . can be a less expensive alternative if shipping distances ar r Flexible Linings. flat. Figure 1. they are by channel highly flow. filter cloth is often used with riprap inhibit soil piping. 4 . Rock riprap is dumped in place on a filter blanket or preRock Riprap: pared slope to form a well-graded mass with a minimum of voids (figure 4). Vegetative channels with sustained low flow and intermittent high flows are often designed with a composite lining of a riprap or concrete lowflow section. grasses are seeded and fertilized according to the requirements of that particular variety or mixture. (figure 2). Figure Composite Channel 2. (Riprap and Jute Net). Information The flexible Permanent on Flexible following channel Flexible Lininas is a summary linings. channel erosion should be determined from service records or from specified field and laboratory tests. of materials currently available for use as Lininqs Vegetative linings consist of planted or sodded grasses Vegetation: placed in and along the drainage (figure 3). shale. If planted. which means that successful revegetation is essential to the Temporary channel linings may be used overall channel stabilization effort.Vegetative and temporary linings are suited to hydraulic conditions where Vegetative channel uniform flow exist and shear stresses are moderate. and organic material. Sod is laid parallel to the flow direction and may be secured with pins or staples. without vegetation to temporarily control erosion on construction sites. In most cases the lining will deteriorate over the period of one growing season. durable. preferably angular in shape. 5 . and free from Rocks should be hard. linings are not suited to sustained flow conditions or long periods of submergence. Resistance to disintegration from overburden. Lining Temporary linings provide erosion protection until vegetation is established. ' ihe material is composed of tough. Gravel Channel Lining. connected together. Wire-Enclosed Riprap. Figure 5. gravel-sized particles and should be free from organic matter. b vary from thin mattresses to boxlike gabions. Figure 6 6. . durabl e. The containers aIr! e filled with stone. Stones must be well graded and durable. Riprap Channel Lining.Figure Vegetative Channel 3. The forms of wire-enclosed ripr ha. Wire-enclosed riprap is typ ii tally used when rock riprap is either not available or not large enough to b t stable. and rei nforced on corners and edges with heavier wire (figure 5). Wire-Enclosed Riprap: Wire-enclosed riprap is manufactured from a re tangular container made of steel wire woven in a uniform pattern. (Class D Retardance). Gravel Riprap: Gravel riprap consists of coarse gravel or crushed ro C nlaced on filter blankets or prepared slope to form a well-graded mass with I 8 minimum of voids (figure 6). and anchored to the channel side slop be. Lining Figure 4. The jute net (figures 9 and 10) is loosely laid in the The net is secured with staples channel parallel to the direction of flow. Jute Net Lining. The net is applied evenly on the channel slopes with the fabric running parallel to the flow direction of the channel.0 by 2. . Figure Woven Paper Net Channel Lining. approximately l/4 inch (0.0 cm). Figure 9. Jute Net: Jute net consists of jute yarn. Installed Woven Paper Net Lining. Installed Jute Net Channel Lining. Figure 7 10. woven into a net with openings that are about 3/8 by 3/4 inch (1.6 cm) in diameter. and by placement of the fabric into cutoff trenches at intervals along-the channel.Temporary Flexible Linings Woven Paper Net: Woven paper net consists of knitted plastic netting'. Figure 7. The net is secured with staples and by placement of fabric into Placement of woven paper net cutoff trenches at intervals along the-channel. interwoven with paper strips (figures 7 and 8). Placement of jute net is usually done immediately after seeding operations. is usually done immediately after seeding operations. 8. with a consistent thickness and an even distribution of fiber over the entire mat (figures 13 and 14). The rovir is ejected by compressed air forming a random mat of continuous glass fiber: The material is spread uniformly over the channel and anchored with asphalti materials (figures 11 and 12). Installed Curled Wood Mat Channel Lining. Curled Wood Mat: Curled wood mat consists of curled wood with wooc fibers. .a biodegradable plastic mesh. Figure 11. Figure 13. Installation Roving Along 4-I ! ia i( of Fiberglass. Curled Lining. and lightly bound together into roving. coated. Roving Figure 12. 80 percent of which are 6 inches (15 cm) or longer. Wood Mat Figure 8 14.Fiberglass Roving: Fiberglass roving consists of continuous fibers drar from molten glass. Fiberglass Lining. a Roadside. The top side of the mat is covered with. The mat is~placed in the channel parallel to the direction of the flOb and secured with staples and cutoff trenches. Synthetic Mat: Synthetic mat consists of heavy synthetic monofilaments which are fused at their intersections to form a blanket ranging in thickness The mat. and anchored into cutoff trenches at intervals along the channel. The mat is secured with staples or wooden stakes. shown in figures 15 and 16. Figure 17. Straw With 9 Net Channel Lining.5 tonnes/hectare) and may be incorporated into the soil Plastic net is placed after mulching with straw according to specifications.0 tons per acre (4.0 cm). Mat Straw with Net: Straw with net consists of plastic material forming a net of 3/4-inch (2. Synthetic Mat Li.0-cm) minimum square openings overlying straw mulch (figure 17). Figure 15. to secure the mulch to the finished channel.6 to 2. is from. Straw is spread uniformly over the area at a rate of approximately 2. Installed Channel Synthetic Lining.1/4 to 3/4 inch (0. laid parallel to the direction flow. Figure 16. . After the mat is in place the area is seeded through the openings in the mat and the cutoff trenches backfilled.ning. Most natural flows are unsteady and are described by runoff hydrographs. which is defined as the ratio of inertial forces to gravitational forces in the system. This allows the flow conditions to be defined by a uniform flow equation such as Manning's equation. Supercritical. DESIGN CONCEPTS The design method presented in this circular is based on the concept c maximum permissible tractive force. high velocity flow. and (3) subcritical or supercritical flow. no change in discharge occurs over time. uniform flow for short periods of time. = Manning's roughness coefficient. P. For design purposes. The method includes two parts. slower velocity flow. design discharge. by the A. approximated slope for uniform flow conditions. R2/3 of uniform flow in a channel depends on the For practical purposes in highway drainage provides a reliable estimate of uniform flow of flow. the depth and discharge remain constant along the channel. . Subcritical flow is distinguished from supercritical flow by a dimensionless number called the Froude number (Fr). Open-channel flow can be classified according to three general conditions: (1) uniform or nonuniform flow. 10 area.flow creates surface waves that are approaching the depth of flow. It can be assumed in most cases that the flow will vary gradually and can be described as steady. the flow may splash and surge in a violent manner and special considerations for freeboard are required. computation c the flow conditions for a given design discharge and determination of th degree of erosion protection required. Supercritical flow (Fr > 1. Resistance to Flow. . and Sf = friction slope of the channel. Open-Channel Flow Concepts Type of Flow.0) is characterized as tranquil and has deep.0) is characterized as rapid and has shallow. (21 steady or unsteady flow. Subcritical flow (Fr < 1. d.49 where . equal to the cross-sectional by the wetted perimeter. channel roughness. engineering. In uniform flow. In steady flow. and channel slope -. divided average bed . For very steep channel gradients. With a given depth puted as: V=7 1.III. the mean velocity may be com- l/2 sf V = average velocity in the cross section. The flow conditions are a function c the channel geometry. Manning's equation conditions. coupled with the hydraulic resistance a the particular lining material. i = hydraulic radius. _ . uniform flow conditions are usually assumed with the energy slope approximately equal to average bed slope. The erosion protection required can be determined by computing the shear stress on the channel at the design discharge and comparing the calculate< shear stress to the permissible value for the type of channel lining used. Depth roughness of a particular lining. n. In general. side of the bend than at the inside of the bend. (7) The water surface is higher at the outsuperelevation of the water surface.6). Retardance Class A presents the highest resistance to flow and Class E pretaller and stiffer grass sents the lowest resistance to flow. Grasses classification of vegetation depending on the degree of retardtice. low-flow resistance. table. (5. examined the biomechanics of vegeprovided a more general approach for determining the Manning's n The resulting resistance equation (see vegetated channels. while short flexible grasses have a species have a higher resistance to flow. surface width of the channel. This superelevation can be estimated by the equation: L bd=sc where V T R: = = = = = superelevation of mean velocity. depth in small channels may be only a few times greater than the diameter of In this case. shallow flows where the height of the roughness features on the lining For a riprap lining. The nature of the shear stress induced by a bend is discussed in The increase stress more detail in the tractive force section on page 13. 5 to 9 were developed from the Kouwen resistance equation. are classified into five broad categories. but is more Design charts studies by Kouwen et al.The discharge in the channel is given by the continuity equation as: (2) Q = AV where A = flow area in the channel. Flow around a bend in an open channel induces centrifuThis results in a gal forces because of the change in flow direction. water Freeboard. gravitational acceleration. The resistance to flow in vegetated channels is further complicated by the fact that vegetation will bend in the flow. as shown in table 1 in chapter IV. is The roughness coefficient will increase for very approximately constant. mean radius of the bend. distance The from the importance . the flow approaches the flow depth (see figure 29). For most types of channel linings Manning's roughness coefficient. Channel Bends. but consideration of the shallow flow depth should be made by using a higher n value. changing the The Soil Conservation Service (SCSI (4) developed a height of the vegetation. requires additional design considerations within and downstream of the bend. equation 19) uses the same vegetative classification as the SCS accurate for very stiff vegetation and mild channel gradients. A channel lined with a good stand of vegetation cannot be described by a single n value. Recent tation and value for appendix B. water surface and Flow around a channel bend imposes higher shear stress on the channel bottom and banks. use of a constant n value is accepthe mean riprap size. surface to The the freeboard top of of the a channel channel at 11 is the design vertical condition. Although some detachment and transport of bed and/or bank materials may occur. based on research investigations conducted by the U. This allows for occur in flow depth for steep channels caused by waves. 12 I . Lining materials should extend to the freeboard elevation. Under such conditions the channel 'bed and banks are in static equilibrium. In a dynamic system. For most highway drainage channels. permissible tractive force procedures became recognized. Methods for evaluation and definition of a stable configuration depend on whether the channel boundaries can be viewed as (1) essentially rigid (static) or (2) moveable (dynamic). this does not preclude attainment of a channel configuration that is basically stable. Two methods have been developed and are commonly applied to determine if a channel is stable in the sense that the boundaries are basically immobile (static equilibrium). Consequently. stability is achieved when the material forming the channel boundary effectively resists the erosive forces of the flow.(L) Permissible velocity procedures were first developed around the 1920's. and defining a channel configuration that will perform within acceptable limits of stability. where sediment supply equals sediment is often referred to as dynamic equilibrium. Bureau of Reclamation. permissible tractive force is the . transport. some change in the channel bed and/or banks is to be expected if erosive forces of the flow are sufficient to detach and transport the materials comprising the channel boundary.of this factor depends on the consequence of overflow of a minimum the freeboard should be sufficient to prevent waves in water surface from overflowing the sides. freeboard height equal to the flow depth. The tractive force (boundary shear stress) approach focuses on stresses developed at the interface between flowing water and materials forming the channel boundary. Steep gradient channels nels. A dynamic system can be considered stable so long as the net change does not exceed acceptable levels. remaining basically unchanged during all stages of flow. bank instability and possible lateral migration cannot be tolerated. development of static equilibrium conditions or utilization of linings to achieve a stable condition is usually preferable to using dynamic equilibrium concepts. This condition.maximum unit tractive force that will not cause serious erosion of channel bed material from a level channel bed. In the 1950's. Principles of rigid boundary hydraulics can be applied to evaluate this type of system. Stable Channel Design or Concepts I Stable channel design concepts focus on evaluating Equilibrium Concepts. In the first case.S. In a permanent about one-half foot of freeboard should be adequate. By Chow's definition. These methods are defined as the permissible velocity approach and the permissible tractive force (shear stress) approach. and for no freeboard is necessary. Procedures for design of vegetated channels using the permissible velocity approach were developed by the SCS and have remained in common use. Stability in a dynamic system is generally attained when the sediment supply rate equals the sedimenttransport rate. Under the permissible velocity approach the channel is assumed stable if the adopted mean velocity is lower than the maximum permissible velocity. However. -cd. (9. and = average bed slope or energy Y s" The maximum shear stress. multiplied by the shear stress in an equivalent straight section of channel where =b The city for giving: relationship a lining (6) can between permissible shear be found by substituting = 0. (7) The average tractive force on the channel.(12) As Rc/B decreases. is expressed by a dimensionless factor. Lp. a more realistic model of detachment cesses occurring in open-channel flow. In a uniform flow. 13 . Kb..rd 'c l/2 P shear stress and permissible veloequation 4 into equation 1 (71 stress. or shear stress is equal to: T = YRS where (4) = unit weight of water. for a straight channel or G&al to the shear stress occurs on the channel at maximum depth. Tractive Force Theory. which impose highct &#ar stresses on the channel sides and bottom compared to a straight reach Pi I)-& shown in figure 19. parallel to the channel bottom. the maximum shear-tress in the bend tends to increase (see chart 10). bed (5) depth of flow. and erosion processes is based on permissible tractive force. Shear stress in channels is not uniformly distributed along the wetted perimeter.distribution of shear stress in a trapezoidal channel tenztoward zero at the corners with a maximum on the center line of the bed. a distance. Rc/B. the tractive force is equal to the effective component of the gravitational force acting on the body of water.In spite of the empirical nature of permissible velocity approaches. the methodology has been employed to design numerous stable channels in the United considering actual physical proStates and throughout the world.101 A typical . tb.189 R1/6 P n ~~ = permissible V where = Kb. and the maximum for the side slopes occurring about the lower third of the side as shown in figure 18: Flow around a bend creates secondary currents. The basis for stable channel design with flexible lining materials is that flow-induced tractive force should not exceed the permissible or critical shear stress of the lining materials. The hydrodynamic force of water flowing in a channel 1s known as the tractive force. the maximum shear sEess is near the inside and moves toward the outside as the flow leaves the bend. and is less than where 'd = rdS d = maximum slope. The increased shear stress caused by a bend persists downstream of the bend. At the beginning of the bend. that is as the bend becomes sharper. The maximum shear stress in a bend is a function of the ratio of channel curvature to bottom width. The bend shear Stress. = hydraulic radius. and are only approximately constant over a range of these parameters. because the failure criteria for a particular lining is represented by a single critical shear stress value. because depth and velocity may be easier to measure in the field than water surface or channel gradient. channel slope. Permissible velocities. ZONE Figure 19. and channel shape. It can be seen from this equation 'that permissible velocity varies due to the hydraulic radius. are a function of lining roughness. Typical Distribution of Shear Stress. However. ~ . permissible velocity is not extremely' sensitive to hydraulic radius since the exponent is only l/6. This critical shear stress value is applicable over a wide range of channel slopes and channel shapes.Figure 18. The simpler representation of failure for the tractive force method is a definite advantage for users who prefer' to use programmable calculators and microcomputers. on the other hand. An accurate solution of the permissible velocity method therefore requires design nomographs. Shear Stress Distribution in 14 a Channel Bend (after -11). The tractive force method is a more compact approach than the permissible velocity method. Equation 7 is useful in judging the field performance of a channel lining. It has been demonstrated that if a riprap-lined channel has 3:l or flatter side slopes. Design of roadside channels should be integrated with the highway geometric and pavement design to insure proper consideration of safety and pavement drainage needs. a combination of shear stress against the bank a?iil the weight of the lining may cause erosion on the banks before the channel bottom is disturbed.are found to be inadequate for the selected channel geometry. typically the mean annual storm (approximately a 2-year return period. i. Riprap and wire-enclosed riprap are more suitable for protecting very steep channels with gradients in excess of 10 percent. there is no need to check the banks for erosion. and therefore is usually fixed. The design method in this manual includes procedures for checking the adequacy of channels with steep side slopes. cross-sectional commonly used for area. For channels outside the roadway right-of-way. Roadside channels with gradients in excess of about two percent will flow in a supercritical state. repairs are easily made. (8) With steeper side slopes. Most flexible lining materials are suitable for protecting channel gradients of up to 10 percent. Channel slope is one of the major parameters in determining shear stress.or lo-year return period. Most highway drainage channels are trapezoidal or triangular ln shape with rounded corners. This can be accomplished by either increasing the bottom width or flattening the side slopes. Design procedures for determining the maximum permissible discharge in a roadway channel are given in chapter IV. The probability of damage during this relatively short time is low. 15 . and top highway drainage channels are Channel Slope. width given Equations for determining of channel geometries in appendix A. the shear stress in the channel with a mild or subcritical slope is smaller than a channel with supercritical slope. and if the lining is damaged. Temporary channel linings 50 percent probability of occurrence in a year). A lower return period flow is allowable if a temporary lining is to be used. wetted perimeter. If channel stability conditions warrant and available linings are not sufficient. the slope may be adjusted slightly.. For design purposes a trapezoidal or triangular representation is sufficient.e.Design Parameters Design Discharge Frequency. For a given design discharge. it may be feasible to reduce the channel gradient slightly relative to the roadway profile. Widening the channel will reduce the flow depth and lower the shear stress on the channel perimeter. Channel Cross Section Geometry. it may be feasible to widen the channel. are often used during the establishment of vegetation. If available channel linings. The channel bottom slope is generally dictated by the roadway profile. Design flow rates for permanent roadside and median dralnage channel linings usually have a 5. and determination of the shear stress at maximum flow depth.e. including rigid linings should be considered. the need of any design aids. A worksheet is provided at the end of this chapter (figure 23) for carrying out the design procedures pre-. Use of side slopes steeper than 3:l is. provided the permissible shear for the lining is not exceeded.: encouraged for flexible linings other than riprap or gabions because of the potential for erosion of the side slopes. It involves only two computations and several straight forward comparisons 0" lining performance. largest riprap size. DESIGN PROCEDURE ~ This section outlines the design procedure for flexible channel linings. Channels lined with gravel or riprap on side slopes steeper than 3:l mus be designed using the steep side slope design procedure. Also. Designers familiar with methods fo determining normal depth may use any convenient method and the Manning' roughness coefficients provided in this manual. The computations include a determination of the uniforrl flow depth in the channel. The basic design procedure is supplemented for riprap lined channels wit1 side slopes steeper than 3:l. The basic comparison required in the design procedure is that of per missible to computed shear stress for a lining. A table and two figures ar provided that give permissible shear stress values for a variety of linin types. If a combination of linings is used. Th computation for shear stress is much simpler and can be carried out withou'. other alternatives.IV. i. Flexible Lining Design The basic design procedure for flexible channel linings is quite simple. Designs involving riprap should be checked and compared to results obtained from design procedures presented in chapter V. other alternatives such as use of addi-tional inlets. 16 : . If a lining is unacceptable. and their vulnerability to failure. a lining with a higher permissible shear stress is selected and the calculations for normal depth and shear stress is repeated. known as the normal depth. If the permissible shear stress is greater than the computed shear the lining is considered acceptable. a modified channel geometry or a flatter channel gradient ar? preferred.. Other linings presented ii this chapter are applicable over a wide range of channel gradients. In cases where flexible linings discussed in this circular do not provide adequate protection. the design procedure must take into consideratio? the additional forces acting on the riprap. A nomograph is also provide in this chapter for determining the normal depth in trapezoidal channels. should be used for design. the composite channel lining procedure outlined in chapter VI should b? used. when riprap is used on steeper gradients. Steep side slope are allowable within a channel if cohesive soil conditions exist. sented in this chapter. Because of the substantial increased cost of rigid linings. Channels with steep gradients (slopes greater than 10%) will usually produce a tractive force in excess of the permissible shear stress for most linings presented in this chapter at relatively small discharges. Steep Gradient Design.no. Channel Ljith steep slopes should not be allowed if the channel is constructed in non cohesive soils. The more conservative results. For larger stone sizes not shown in chart 1 and rock riprap. underlying soil is relatively protected. hydraulic radius. indicates the force required to iniPrior to movement of the lining. The range of flow depths from 0. Table 3 gives recommended values of the Manning's roughness coefficient for flexible channel lining materials. The consequence of lining failure on highly erodible soils is great. including riprap-type lining materials. the tiate movement of the lining material.Permissible Shear Stress The permissible shear stress. if the lining is eroded and moved. and friction gradient which. Therefore permissible shear stress is not significantly affected by the erodibility of the underlying soil. for channel bed gradient. the permissible shear stress is given by the following equation: =P = 4. the chanusing Manning's Roughness Coefficients for Nonvegetative Linings.5 ft (15 cm) to 2. S. chart Flow Depth' The condition of uniform flow in a channel using the Manning's equation combined with Q =L$AR where Normal feet. Table 2 presents permissible shear stress values for manufactured. provides a good guide to the per- = = = = = at a known the continuity 2/3s f l/2 com- (9) discharge. 17 . For cohesive materials the governed by many soil properties. The n values will vary with flow depth. since the erosion rate after failure is high compared to soils of low erodibility. vegetative.0 ft (60 cm) is typical of highway drainage channels and should be used in most cases. Chart 3 provides a solution. equals to Manning's equation for trapezoidal of a trapezoidal channel can be found in appendix A. erosive force of the flow. Tp. Values for permissible shear stress for linings are based on research conducted at laboratory facilities and in the field. The values presented here are judged to be conservative and appropriate for design use. Determination puted of Q : R Sf nels. and riprap lining types. Manning's roughness coefficient. The permissible shear stress for non-cohesive soils is a function of mean diameter of the channel material as shown in chart 1. the bed material is exposed to the However. The channel roughness will be higher for shallow flow depths and lower for large flow depths. cross-sectional area. The geometric properties 4 or the equations provided discharge is equation: uniform flow conditions.0 D50 (8) where is the mean riprap size in D50 variation in permissible shear stress is The plasticity index of the cohesive soil missible shear stress as shown in chart 2. at Tractive maximum Force depth. the lining material becomes less stab1 !.he value must be determined by tr-al depth of flow and the flow force. K2 is size (mean diameter of the gradaiion the following equation: the ratio of the she lr of the channel. is giv m given in chart 14. is computed = rdS the shear using the (5) = unit wei ht of water (62. Side Slope Stability Channels lined with gravel or riprap on side slopes steeper than 3:l m ‘Y As the angle of the side slopes approaches the angle become unstable.Manning's Roughness Coefficients for roughness coefficient for vegetative linings the amount of submergence of the vegetation As a result. the ro' :k The angle of repose. imposes higher shear stress on the the maximum shear stress is given = Kb~d channel by he 1 (6) where the value of Kb can be found using chart 10. and = channel gradient. Manning's varies significantly depending on and the flow force exerted on '. However. the shear stress on the channel si-de is less than the maximum she lr stress occurring on the channel bed. determine the magnitude of factor Kb. The stability of a side slope is a fun' :tion of the channel side slope and the angle of repose of the rock lini 19 material. n for five classes of vege:aManning's n for a wide range of lb/ft3). Td. The length of protectio 1.4 = flow dep 8 h. following equation: =b Vegetative Linings. rock shapes and sizes is provided in on the sides and bottom of a trapezoidal and the tractive force ratio. B. I '3 chart 12. Theory (page 131. Lp. required downstream of a bend is found using chart 11. The ratio . ft/ft. Determination of Shear Stress As presented in chapter stress on the channel lining following equation: 'd where Y : on Channel III. n and error taking into consideration both the Charts 5 to 9 show the variation in Manning's tion. These charts can be used to determine flow conditions. KI . For bends. and the bottom width of t te channel. Flow around a channel bend bottom and banks. T te D50) for the side slop1 !S (10) 18 .f repose of the channel lining.f channel. the Manning's channel bed. The length of pr tection is a function of the roughness of the lining material in the bend (n 5 and the depth of flow. . the radi' IS of curvature of the channel center line. Rc. In chart 10. ft. When the stress on the size for the for different shear stress in chart 13 required rock is found using tractive force ratio is compared to sides to the shear stress on the bottom channel side slope can be determined. filter 5 < D85 base D50 filter riprap is The filter fabric. The thickness of a riprap lining should equal rock size in the gradation. presented is for both vegetative the procedure for vegetative not involve a trial and error for Riprap design gradation linings and non-vegetative linings is particularly usesolution. D15 filter l)l5 the used the material following < 40 the diameter of the largest this will mean a thickness criteria need for an underlying may be either a granu- must be met: (11) base < 4.will fall in the range of size distribution curve.0 to 1. By knowing the maximum discharge that a lining can sustain. economic evaluation of lining types and can determine inlet spacing.0 times the mean riprap diameter. since it does Design Considerations Two additional linings: (1) riprap under rock riprap. preventing the formation of open pockets. the designer simply needs to know the maximum discharge a channel can convey given the permissible shear stress and the corresponding allowable depth. the designer can determine the maximum length of lining for a channel. of from 1. An approximate guide to stone shape is they are easily dislodged by the flow.5 to 3. The procedure linings. Filter Design. riprap constructed with angular stones has the best performance. Most riprap gradations . The most and D&D20 DlOO&O important criterion is a proper distribution of sizes in the gradation so that interstices formed by larger stones are filled with smaller sizes in an These gradainterlocking fashion.5. are and required for (2) use of riprap filter channel material Riprap gradation should follow a smooth Riprap Gradation and Thickness. between 3. based This information can assist the designer in an on the hydrology of the site. which is acceptable. For most gradations. neither the breadth nor thickness of a single stone is less than onethird its length. (12) D50 base 19 . tion requirements apply regardless of the type of filter design used. blanket. Round stones are acceptable as riprap provided they are not placed on Flat slab-like stones should be avoided since side slopes steeper than 3:l. that. Lining considerations and thickness. In general. Applying ful.Maximum Discharge Approach In many cases. When rock filter material must be evaluated. lar filter blanket or a engineering For a granular D15 filter. For soil with more than 50 percent of the particles a U. by weight (greater or be non-critical designed The procedure passi 19 that # 50 install 1based on pe "- Procedures The linings is design procedure a basic stepwise is summarized below. No. solution approach. (Use chart and Appendix A for other shapes. 6. .024 Std.297 mm (0. (AOS) must be met: particles by weight passi '9 in) (greater than #30 U.012 in) U. (18) - 1. flow depth the channel 3. the fabric should be able transmit water from the soil and also have a pore structure that will hc E back soil. material The thickness of the granular mum size in the filter gradation.) n from Chart 5. "filter" material. 200 sieve. slope n value linings. material 2 nd hold betwc en and fill er refers to the overlying The relationships must and between the riprap filter blanket should The minimum thickness approximate for a filter the mar iblank et In selecting an engineering filter fabric. The following properties of an engineering filter fabric e re required to assure that their performance is adequate as a filter und ar riprap. Desian be able for only critical transmit the applies insta water faster apparent to llat than opening non-severe ions should size the soil. Select a flexible (see Table 2) 2. 3.S . the hydraulic rad ius. Sieve). AOS < 0. for flexib le FLEXIBLE LINING DESIGN PROCEDURE (see computation 1. non-vegetati 'c P* ve depth. No. 200 sieve.. 7. R. estimated use Table flow shear for stress.S.In the above relationships. - must to criteria The above criteria tions. The following a. Estimate linings. or 9.S.S. For soil with less than 50 percent of the a U. should not be less than 6 inches.6 mm (0. Severe or meability tests. Determine Manning's For For (1) non-vegetive vegetation: Calculate channels Determine i: (2) sheet. Std. Sieve). b. 8. "base" refers to the underlying the filter blanket and base blanket. 4 for trapezoid 31 . AOS < 0. figure lining 23) and determine for vegetation shape. The fabric 2. for the permissible or flow depth range and design discharge(s). the ratio of maximum side shear to. For channel bends: a. of protection. outside the assumed range for non-vegetative linings or differs than 0. d. Calculate the shear stress in the bend. (3) or gravel linings on steep side slopes the angle of repose for (steeper than 3:l): a. downstream of the bend from superelevation. b. Compare computed flow depth. in the shear stress. Tb.4. This is a function bottom width. the channel. Determine the factor for maximum shear stress on channel bends. "b = Kb Td (6) If 'b > Tp. 21 . check design procedure in chapter v. the flow depth. Rc/B. di. the lining c. the tractive d. steps 1 through 7. repeat steps 2 through 4. Determine 12. trapezoidal If d is by more is not accep- Td = rdS 7. Determine Kl. Calculate 'table. (10) Kl (D5O)sides 9. 6. Calculate Ad = a. of the ratio of channel curvature to from chart 10. c. Calculate length chart 11. ^Cd. If (Chart 3 for the lining Td > Tp. with estimated flow depth. D50 for the side slopes.maximum bottom shear for a trapezoidal channel from chart 13. Calculate the required force =G the rock size and shape from chart ratio from chart 14.1 ft from di for vegetation. Lp. b. Determine K2. d. For riprap is not acceptable. V2T gR. Kb. repeat (D50)bottom For riprap on slopes greater than lo%. Use whichever procedure results in the larger riprap size.) 5. d. repeat steps 1 through 5. Calculate channels. 27 lb/ft2 22 stress on the channel . d/B = 0. Solve Manning's equation for the channel. enter into charts 5 to 9 for the correct vegeta tion class and determine the Manning's n value. Determine the area and hydraulic depth using chart 4.4 0.5 to 2. and 3:l side1 in the channel and the adequacy of the jute net lining (1) From tab1. (2) Entering chart 3 for S = 0. The flow depth has remained within the range of 0. (equation corresponding 9) to determine to the allowabl 14 the maximum discharc Examole Problems Example 1: Determine whether it Given: Find: Solution: is feasible Q = 20 ft3/sec s = 0. Determine the allowable depth of flow in the channel using the permissible shear stress (table 2 or charts 1 or 2). maximum depth is. find the correct Manning's n from table 3 For vegetative linings.005 ft/ft Trapezoidal channel with slopes. the permissible shear stress lb/ft2 and from table 3.44.22 d = 0.0). radius 3. Check that this dept does not exceed the depth (including freeboard) provided in the typica roadway section. the Manning's n value (assuming a flow depth between 0.88 ft Qn = 0.02 and B = 4.0 ft so that the assumed Manning's n value is correct. Depth of flow to use jute net as a temporary a bottom width of 4.88 x 0. (3) Using equation 5.4 x 0.e 2.005. is is 0.0 ft lining. For non-vegetative linings..5 to 2. 4. 'd the shear = rdS = 62. MAXIMUMDISCHARGEDESIGN PROCEUDRE 1.bed at . d = TP ys (13) 2.005 = 0. to the permissible that jute net is an accep- 2: Determine if quate lining a for single application a median ditch. the flow depth and Manning's n for the depth at design discharge. x 0.0 ft z" =4 23 Determine . stress. 5 is. Given: B = 2 ft z=4 = 0.028. Given: Q = 20 ft3/sec S= 0.05. = 0.0 is n 0.005 ft/ft = 4.05 The permissible shear stress Since this is less than the is not adequate.21 and B = 2 d/B = 0. Manning's of 0.27 shows Comparing the shear stress.05.28 and B = 2 Qn d/B = Do.24 d= 0.48 ft (3) The computed flow depth The maximum shear stress 'd (4) Example = YdS = 62.45 lb/ft2. shear stress. table channel lining.0 to 0.05 ft/ft G = 10 ft3/sec Find: Depth Solution: (1) (2) of of fiberglass roving lining is an ade- flow. the lining 3: A roadside ditch is lined with a good stand of uncut buffalo grass.48 is within from the equation assumed range. Enter chart 3 for S = 0.42 ft given Checking the flow depth against the initial assumed range The shows that the computed depth is below that range. On = 0. Manning's n for flow depth range of 0. for fiberglass maximum shear is 0.5 lb/ft2 x 0.5 ft is 0. lb/ft2.021 assuming a flow depth in ft Entering chart 3 for S = 0.6 lb/ft2.(4) Example 0.21 d= 0. From table the range 3.4 = 1. 0.5 to 2. 65 R= (3) channel.066 (41 Entering chart I 3 given S = 0.65 and S = 0.44 (5) Since the difference depths is 0.76. (2) Flow in the depth The vegetative good stand of retardance uncut buffalo The determination lining may require Trial 1 (1) Initial (2) From chart R/d = 0.0 Z = 4 and d/B flow found in table as retardance depth for 1. ft chart 8 given R = 0.98 and S = 0. B = 4.1 ft. depth Entering ' is 4 for and n estimated at 1.005.60 ft is from and calculated repeated. D. n = 0. between which is 24 the initial greater than and calculated 0. classification is grass is classified of Manning's several trials.40.005.1 calculated chart between ft. dure is repeated.32.65 0. and B = 4.Find: Solution: (1) Manning's n value. the proce- I .005. d/B = 0. the depth 4 for of Z = 4 and the initial procedure 1. R/d = 0. trial depth 1. A a vegetativ ft.60 (5) 2 (1) Use the (2) From S = 0. I n = 0. Qn = 1.61 R= (3) 0.l ft Since the is greater Trial 3 given difference than 0.98 Entering chart 8 given R = 0.25.40 d = 1.088 (4) Entering I chart d/B = 0.005. I d/B = 0. and Z = 4.36 d= 1. Qn = 1. = 0.16 ft. n = 0.070 i = 1.45 lb/ft2 = 0.44 d/B ft from trial 2.0 3.Trial 3 (1) Use the (2) From calculated chart depth 4 for of Z = 4 and 1.48 The The (5) initial procedure Qn = 1.37 d = 1. and B = 4.88 chart 3 given S = 0.03. ft depth and the is completed calculated with the depth are in agreement.005. R/d = 0.88 Entering (3) chart 8 given R = 0. following results. Solution: Trial (1) 1 Jute net permissible are. specified range for .35.03 ft/ft B = 4. given the n alternative. is range from slightly channel lining and Manning's of 0. '1 (2) is selected as an initial shear stress (table 2) = 0. and S = 0.5 ft Example Determine 4: a temporary channel Given: Q = 16 ft3/sec s = 0.005. = 0. value (table The 3) ft) S = 0.36.61 R= 0.0 ft z=3 Find: Adequate temporary lining for channel a trapezoidal channel. and B = 4. d/B = 0. = 0.5 chart below 25 to 2.022 (assuming The On = a depth flow depth is determined 0.40. lining.070 Entering (4) d/B = 0.48 ft The flow Manning's depth n.12 d = 0. 56.48 lb/ft2 x 0.55 = 0. (3) a depth depth is determined B = 4.030.12 lb/ft2 lbJft2.55 1.4 = 0. (4) range ft The flow depth value used. of the . d/B = 0.15 d = 0. = 1. given S = 0.035 The (2) lblft2 (assuming flow 0. Fiberglass roving was not chosen since its permissible shear stress was less than the calculated shear stress from the first trial.(3) The = 62. (2) The lining superelevation required of the for water 26 the bend surface and in the the location bend.60. On = The 'd Use of Example is shear stress = 62.5 from to chart 2. so jute net would not be an 2 (1) The next lining chosen is curled wood mat because the permissible shear stress for this lining exceeds the calculated shear stress from the first trial.12 x 0. worksheets specified depth range is found for using the Manning's equation n 5.03 The computed shear stress missible shear stress of acceptable channel lining.90 lb/ft2 is greater than the per0. 5: Determine an acceptable 4 if a bend is included 45" RC Find: depth Trial 2 Given: maximum channel = 20 ft in channel lining the channel for the alignment.4 = 1. 0. is found using equation 5. The permissible shear from table 2 and the Manning's n from table 3 for curled wood mat are. so problem is is less than the percurled wood mat is an illustrated in figure 21. roadside channel in example bend (1) The channel lining. lb/ft2 within at the maximum the of 0.45 lb/ft2. of 0. and Z = 3.90 'd (4) shear stress at x 0.03 The computed shear stress missible shear stress of acceptable lining.60 for this of 1.0 ft) 3. The shear stress in the bend is given by equation 6.0 ft. 'b = 1. the shear stress reach upstream of the bend is. The value of 6 is found from chart 10 given R.12 = 1.55 lb/f+ (4) The calculated bend shear stress is less than the permissible shear stress for synthetic mat of 2.6 x 0.40. because it is permissible shear stress from table 2 (2.5 to 2. 27 . and B = 4.13 d= 0.03 = 0. =b = 1. (3) The shear stress within the from equation range originally assumed for 5. Trial 2 (1) Synthetic mat is chosen as a bend lining material.0 lb/ft*) is greater than the computed shear stress from./B = 5.55 A new lining is required for the channel bend. Kb in equation Kb = 1.12 lb/f+ A curled (2) wood mat lining was used to stabilize the channel.025 for a flow depth range from 0. of the straight 'Id = 1.52 ft This depth falls Manning's n. trial 1.6 The bend shear stress is. Synthetic mat therefore provides an acceptable channel bend lining.6 x 1.79 lb/ft* (3) The computed shear stress in the bend is greater than the permissible shear stress for a curled wood mat channel lining (1.03. lb/ft*).4 x 0.52 x 0.97 lb/ft* The bend shear stress from equation 6 is.Solution: Trial (1) 1 From the results of example 4. (2) Entering chart 3 given S = 0. The Manning's n value is 0. d/B = 0. Qn = 0.97 = 1. 'd = 62.0 lb/f@. 0/2. T= of Flexible Linings for Example the water surface is computed 3. nb. in the channel found V = Q/A = 16.5 ft/sec 28 using the continuity equation .89 ft2 The velocity (equation 21.522 = 2.52 = 7. mat will extend through The downstream distance is R = 0.4 ft The total length of in the bend plus the The following figure materials.40 (from chart 4 for the bend and a distance found using chart 11.1 ft and A= Bd + Zd2 = 4 x 0. given d/B = 0. top width and cross-sectional from 5.9 LP = 6.89 = 5. equation area must B + 2Zd = 4 + 2 x 3 x 0.(5) The synthetic downstream.52 + 3 x 0. STRAW 4 --- WITH synthetic mat lining is the sum of the length required for downstream protection. OF CURVATURE Location \ Sketch The superelevation of 3.13 and Z = 31. To execute equation be computed. where. shows the required location of lining length NET FLOW STRA CENTER Figure (6) 20. Lp/R = 15.025.= 0. 4 inches slope = 5. Given: to gravel channel Find: Example figure ft 6: Because of a width constraint on available right-of-way. equation angle side the of shear tractive repose to bot- force 10 is.0) = 2.Solving equation 3 given V = 5. (4) The side ft slope. necessary to protect the ditch banks. 2 x 20 = = 0. = 0. Given: 0. Ad 5A2 x 7.65 Z required side D50 = E5 (2. 7: Determine the maximum allowable discharge for a median stand of Kentucky bluegrass (approximately 8 inches in a depth of 3 feet from the roadway shoulder. the ratio 8 of = 36".7 D50 for Solution: (1) Fary3$art (2) From chart tom shear.79 B/d chart 14 given K2 = 0. d = 0. T = 7.5 ft/s.1 . The e-inch roadside ditch must be steepened to 2:l. (3) From ratio. D50. the side slopes of a gravel lining has been Determine the gravel ft depth. The ditch has .33 S = 0. illustrated in Very rounded A trapezoidal z = 2 B = 3. Ad= V’T -4R.167 the = 2 and D50 from ft.010 ft/ft B = 4. and Rc = 20 ft. determined to be adequate to protect the ditch bed.0 ft z=4 29 ditch lined with a good height).0. 12 given a D50 13 given K1 = 0.33 ft The freeboard accommodate Use of Example the in the worksheets the channel superelevation for this bend should of the water problem is be at least surface.5 Flow 21. size.1 ft. 4 i%ct~$e 5 < (1) (2) (3) (4) (5) (6) (7) Table 2 For vegetation.=zo’ di R n (2) (3) (4) (. table 3 Normal deptn.wple PROJECT: Pvob\eMs 4 $5 STATION: TO STATION: DRAINAGE AREA: DESIGN FLOW: ACRES = Q ftj/sec DESIGN FLOW FOR TEMPORARY LINING: CHANNEL SLOPE (S) CHANNEL DESCRIPTION: Q LINING : -03 (1) 16 = ft3/sec ft/ft v Tp 2 Q brtNd =e” I 3’ R. charts 5-9 For other liners. / Ebccwple. Worksheet for Example 30 Problems 4 and 5 REMARKS . select range from table 3 Vegetation only. chart 3 (d must be in di range) Td must be < Check for sreeGPside slopes and channel bends Figure 21.YS.Worksheet for Flexible DESIGNER: Lining Design DATE: Exa. estimate initial depth For other liners.) j Td. chart 4 for trapezoidal channels For vegetation. & .0049 ft D50 = 0.66 ft D15 = 0.61 0. = 33. given Tp/vS = Q depth from equation Gradation D85 = 1..00 62 4 x 0.072: the Manning's equation with _ I. as retardance C.00055 ft 31 continuity (equation 91.98 (4) Solving the need for than the depth of the 2.3 ft D50 = 0.011'2 = .010 = 1. .. (1) From table 1.Find: Maximum allowable Solution: discharge.5 mm = 0. Riprap Gradation 085 = 1.6 (3) From chart Given: Td = ~~~ 1.00 lb/ft2 Determine d= the allowable ft Note that ditch.6 x 0.149 .98 2/3 x o.6 0.@3S1/2 x 16.33 ft Base Soil radius 16. From table 2 the permissible =P = 1.40.0016 ft h5 = 0. A/Bd = A= R/D = R= depth is less area and hydraulic 7: from chart n = 0.5 mm = 0. a good stand of Kentucky bluegrass is classified shear stress. 4.167 mm= 0.9 cfs Example 8: a granular filter blanket. Determine 5. the allowable (2) Determine the flow given d/B = 0. 00055 = D50 base 0.7 ft (7. ft (6. satisfy: filter' respect to 0. so D 15 filter< 40 X 0.064 40 X 0. D15 riprap 67.3 mm) mm) ft (0.22 required material.0082 32 - ft (4.33 ?TJ- = 0. First. determine the required dimensions of the filter to the base material.83 the filter mm) mus ft ft filter I dimensions with respect t P D50 riprap " = 0. D50 filter ' 40.Find: Solution: Granular filter blanket requirement.66 = 600 not less than 40 = 412 not less than 40 UXU1o Since the relationships between riprap and base do a filter blanket recommended dimensional criteria. < 40. D50 filter 0 15 f-1t riprap 15 1 er 40. the riprap. SO D50 filter' = 0.00055 D15 filter D85 base '15 filter '15 base ' 5s So D15 filter ' 5.022 So D50 filter' 0.66 -4(J- = 0.5 mm) mm) .4 '85 D 15 riprap D15 base D not less than 5 base 50 riprap 0.0016 not meet is with ft (20 mm) D50 base '15 filter D15 base < 4.016 so 0 15 filter> 0.064 < D15 filter the < 5 x 0.9 ft (2.0028 ft determine Second.0028 base < 0.0049 the D50 filter = 0. 5 ' o*ooo55 = 0. . SO D15 with Therefore.33 = 0-.024 < 0. 066 ' O.9 mm < D50 filter .0 for illustrated The qradation requirements blanket specifications are the resulting in figure < 6.5 mm < D15 filter (4.O66 ft ft ft Combining: 0.066 ft (20 mm) D15 filter' 0.33 3- = 0.33 F = 0. filter '* '85 15 riprap '15 ' 5y '* filter With respect to the riprap: 0.016 < 0.066 ft (20 mm) D15 riprap '85 D ' 5.022.(D85 filter > 20.5 mm) granular mm) mm) filter 22.0082 ft D50 filter < D15 filter 085 filter > 0. Gradations Example 8.016 ft ft < 0.ft < 0. Filter design for base material Filter design for riprap material 4 6 8 10” 2 4 6 810a 2 4 PARTICLE Figure 22.064 ft > 0.7 < 19.066 ft < D15 filter < D50 filter D85 filter (2.0082 0. of 6 8 10’ SIZE 2 4 6 81az 2 4 6 8103 (mm) Granular Filter Blanket for 33 : d .filter' 0. rma~tdq$h. chart 3 (d must be in di range) (y) C’he’c”ku for (3) (4) s*eep Figure TP side 23. chart 4 for trapezoida For vegetation. estimate initial depth For other liners. slopes and channel Worksheet for 34 Td=YdS (6) bends Flexible Lining Design REMARKS .di (2) R n d (3) (4) (5) ISi Table 2 For vegetation. select range from tab le 3 1 channels Vegetation only. table 3 N. charts 5-9 For other liners.Worksheet for Flexible DESIGNER: Lining Design DATE: - PROJECT: - STATION: TO STATION: DRAINAGE AREA: DESIGN FLOW: ACRES = Q ft3lsec DESIGN FLOW FOR TEMPORARY LINING: CHANNEL SLOPE - (S) Q = f t3/sec ft/ft : CHANNEL DESCRIPTION: LINING Q 'p (1) (1) (2) . blue gamma..and..... Lespedeza aericea ..... Crabgrass ............dG. Grass-legume mixture-summer (orchard grass....... and other long and short midwest grasses) . bluegrass .. Bermuda grass ........... uncut (average 11”) (28 cm) Good stand. Good stand....... Bermuda grass .. (5) Cover ?tardance lass Condition Weeping lovegrass ... ... Excellent stand..... Very dense Good stand... Commbn leapedeza . uncut (4 to 5 inches) After cutting to 2-inch height Very good stand before cutting Good stand....... Good stand....... Good stand.. redtop....... cut Burned stubble in experimental 35 (15 to cover (average 6 inches) (15 cm) headed (6 to 12 inches (15 to 30 f-1 Excellent (6 to 8 inches) (5 cm) to 1.............$ytand. tall (average 30”) (76 an) Excellent stand......... Weeping lovegraaa ........ Bermuda grass ... Blue gamma ..... Buffalo grass ....... spring (orchard grass.......... Good stand......... tall uncut (average 12”) (30 cm) unmowed not (average 24”) (61 cm) tall (average 19”) woody. uncut (average 13”) (28 cm) Fair stand.......5-inch height (6 cm) stand... Common leapedeza D as to Cover8 ser icea .. redtop. Covers classified have and generally uniform. uncut Centipedegrass .......... Weeping lovegrass ............ Yellow blueatem Iachaemum . unmowed (average 13”) (33 an) Dense growth... Italian ryegrass........5 inch height channels.. Classification Degree of Vegetal of Retardance....... bluestem. t... Leapedeza NOTE: tall uncut (10 to 48”) (25 to 120 cm) mowed (average 6”) (15 cm) uncut (average 11”) (28 an) Kentucky E growth.... Alfalfa . Bermuda grass ........... been tested cut to 2.. Good stand.... Grass-legume mixture-fall..... Native grass mixture (little bluestem..... tall (average 36“) (91 cm) Kudzu Very dense .......... Good stand........... (10 to (4 cm) Covers were green ... fy$Ttand... and coirmon lespedeza).....Table 1... Bermuda grass . Fi.. and common leapedeza) ... Kudzu ..... uncut (average 4.......$ytand........... Italian ryegrass... ... Good stand........ uncut Good stand................5”) (11 an uncut (3 to 6 inches (8 to .. 45 l-inch in 0.55 2. 1 2 .45 1 .33 0.60 0.oo 9.25 Z-inch 0.88 2.85 4.60 0.00 9.15 7.15 0.76 19.61 3.67 1. Permissible Shear Stresses for Lining Unit Lining Category Lining Temporary* Gravel Class Class Class Class Class Riprap Bare Soil 'Based on data *Some "temporary" (Kg/m2) A B C D E 1.08 7.52 8.oo 0.71 Non-cohesive Cohesive (5.Table 2. 0.73 2.20 1. permanent 36 when buried.06 2. linings 0.76 3.70 18.35 Riprap Rock ~ Permissible Shear Stress' Type Woven Paper Net Jute Net Fiberglass Roving: Single Double Straw with Net Curled Wood Mat Synthetic Mat Vegetative Materials.22 6-inch 12-inch 2.57 2 .00 4.93 4.93 1. -'13 -'14 become See Chart See Chart -15).10 10. . (after DIAMETER.Chart 1 D(h) 4 .oos I 1 ‘.1 I I 1 I III 0.lO . Permissible soils. shear stress 15) 38 I I I 10 I Ill60 D(mm) for non-cbhesive 10 0 .Ol ‘I I ’ .6 I 1 I I II I S PARTICLE Chart I 1.’ .os I .50 I I ““I 1.0 I ““I * 3 0.01 c 0. Chart 2 Loose 0.P. . for cohesive soils.I A I t L _ PLASTICITY Chart 2.I. .5 N = Number of blows required to effect 12' penetration of the 2" split-spoon sampler seated to a depth of 6" driven with a 140 lb weight falling 30'. Permissible (after 16) INDEX shear stress 39 . Solution of Manning’s equation for channels of various side slopes.0 / lo8 0/ 6 3.05 I.d Chart NOTE: 3 Project horizontally to obtoln valm fa from 200 scale 2: I to 6 B (-1 S 40.14(4)-0.’ 0’ / SOWTION: Qn = 0.1 0.0 5. (after 17) 40 . Qn I.05 0.Ol EXAMPLE: FIND: d Q=lO FT3/S n = 0.14 d =0.3 d/B ‘0.06 20 I.03 10 8.0 4.0 I.06 0.0 /’ 5 2.1 Lo8 30 (FT3/S) 3 20 I.04 I.01 i 0’ / GIVEN: / 0.56 FT FT 2=4 0.04 01’ S=O.08 0.03 B=4 .02 Chart 3.02 6.03 t 0.0 / p. 60 0.4 0.9 ft.0 10.14 I 0.05 A/Bd -2.0 20 P .40 I/ d/B n/I 0.10 0.12 d = 1 ft..0 1. 0.06 Then: 0.09 0.7 0.18 0.8 1.20 0.80 0.0 3.08 1 I I IIIII I / --I-74 Example: 0.2.50 0.6 1.02 0.0 0.16 0.07 0.4 2.50 0.04 0.30 0.14 0.40 1.70 0.12 I ill 1: / LB 1 ’I 0.0 2.0 5. 8. B .10 0.2 I.4 I I I II \\m 0.62) (1) = 0. Geometric 4.90 0.0 R/d Chart 4.9 0.35 0.2.0 1.06 R/d= 0.9 1.20 0.07 0.08 z=4 0.5 0.0 6.6 1.16 0. + 0.0 1.62 A = (0.90 0.16 I 0.6211.70 0.2 1.04 0.0 0.30 0.03 0.0 AlBd design chart for trapezoidal channels.09 = 0.05 0.80 1..60 0. Chart 5 42 . 43 Chart 6 ? v) 9 t ? cr) 0 ? m & 1 0 . I ! I! -1 t if! -i 1I f 1 -t I -1 I .Chart gEj!E I 7 1 : -J-j--t---- I -- c 44 .j1i*. --. --.--+-p3 I ! n.30 .20 II .-. / --.- ---.. - -.-_ t- 4-z\ G l .__ ---_~--_--... for class D vegetation.50 8.-..OlO ... .lO Chart .--- - ---_.1.----1.40 ._.6+19. -__-_. . ._. -.. R..__._.----.-. --.-_.--.-----.70 hydraulic radius. .-.4) ij I ’ D---t .9710g(R’*4S0.-.. Manning’s n versus (after 5) i ‘___ ’ j -.-.34. Chart 9 46 . Kb factor for maximum shear on channel bends.O . .2 - 1.8 ll-t-i-? t-----t-iI \ 1.5 1. (12) 47 stress 10 . 1.Chart 2.7 _ 1.4 1.1 l.Q 1.3 .O0 1 Chart 2 3 4Rc5 s 6 7 8 IO.6 1. 48 Lp. r.y. downstream of channel bend .Chart 11 \ h nb= Manning Roughness in the bend c “b 0.0 Lp/R Chart 11.yCtion length.01 1. 49 1 0 (60 IO 80 in terms of mean size . Angle of repose of tiprap and shape of stone. 41 0 Chart 12 04 / 36 L 3i 3! 3: 3' 6 8 10 : MEAN Chart I I 0 60 STONE 50 SIZE. FT..mm 12. D50. D50. MEAN STONE SIZE. 8 0.. (8) to bottom she.0 0.5 0 2 4 6 8 10 B/d Chart 13.Chart 13 1.9 J@I II c 0.7 0. Channel side shear stress stress ratio.1 I I I I I I 1. K.6 0. . Chart 25 20 . Tractive 51 force ratio. 4 ii E t I - 8 b.I 10 Chart 14. Kzj8) 14 . On a steep slope.5. A worksheet is provided at the end of this chapter (figure 25) for carrying out design procedures in this chapter. such as foundation and maintenance requirements for the steep slope channel lining. Because of the linings for steep gradients. riprap. The decision to select a rigid or flexible lining may be based on other site conditions. The primary forces include the average weight of the stones and the lift and drag forces induced by the flow on the stones. results obtained using the previous design additional forces acting on riprap. the wire mesh may be abraded and eventually fail. This permits use of Of course smaller stone sizes compared to those required for loose riprap. A design requiring a bend in a steep channel should )e reevaluated to eliminate the bend or designed using a culvert. The size of riprap and gabion linings increases quickly as discharge and channel gradient increase. a stone within the riprap will tend to move in the flow direction-more easily than the same size stone on a mild gradient. Rigid channel linings may be a more cost-effective alternative in thle case of steep slope conditions. Bends should be avoided on steep gradient channels. Steep Slope Design Riprap stability on a steep slope -depends on forces acting on an individual stone making up the riprap. using a safety factcr of 1. the stability of gabions depend on the integrity of the wire mesh. steep slope channels require larger stones to compensate for larger forces in the flow direction and higher shear stress. Gabion mattress stability on a steep slope is similar to that of riprap tend to act as a single but because the stones are bound by wire mesh. STEEP GRADIENT CHANNEL DESIGN I Achieving channel stability on steep gradients usually requires some typ of channel lining except where the channels can be constructed in durabl This section outlines the design of two types of flexible channe bedrock.v. In strearis with high sediment concentrations or with rocks moving along the bed of the channel. Movement of stones within a gabion is negligible. procedure should be compared to the steep gradient procedures when channel gradients approach 10 percent. Hence. the weight of a stone has a significant component in the direction of flow (see figures in appendix Cl. Extent of riprap or gabions on a steep gradient must be sufficient to protect transition regions of the channel both above and below the steep gradient section. Applications of gabion mattresses and baskets under these conditions should be avoided. Under these conditions the gabion will no longer behave as a single unit but rather as ind*vidual stones. Because of this force. A description of the factor of safety method and the assumptions mace in developing the design charts is presented in appendix C. for a given discharge. they unit. The riprap design procedure is based on the factor of safety method for riprap design. and gabion mattress. The transition from a steep gradient to a culvert should allow for slight movement of riprap or slumping of a gabion mattress. Other Considerations for Steep Slope Design Channel Alignment and Freeboard. 52 . For channel widths not given in charts 15 to 18. 2. thickness and filter requirements are the same as those for mild slopes. (7) Freeboard should equal the mean depth reach approximately twice the mean depth. To determine flow use the following depth steps: and a. wave height will height should be Gradation. For channel bottom widths in excess of 6 feet. since This freeboard installations. used for both temporary and permanent channel of flow. Design given Procedures A stepwise for steep guideline with complete references slope riprap and steep slope gabion to charts and figures mattress designs. Find values of the to the side charts. the riprap A3/Az slope size D50 = d using ratio are found from table 4 (the z-value) and di is the flow depth the formula: (14b) D5Oi 7 where di and D5Di are subscript from the values from 53 the design charts. The transition from a mild gradient to a steep gradient should be protected against local scour upstream of the transition for a distance of approximately five times the uniform depth of flow in the downstream channel. The transition from a steep gradient channel to a mild gradient channel may require an energy dissipation structure such as a plunge pool. the rock gradation used in gabion mattress must be such that larger stones do not protrude outside the mattress and smaller stones are retained by the wire mesh. . is STEEP SLOPE RIPRAP DESIGNPROCEDURE 1. enter chart 15 to 18 for correct For given discharge and channel slope. formula: (14a) di -A. Also. Riprap gradation. where refers design .b. channel shape and determine the flow depth and mean riprap size. depth using Find the flow d = A3 riprap the size for side slopes greater than 3:1. use the more detailed design procedures in Appendix C. It 'is important to note that riprap thickness is measured normal to steep channel gradients. and Filter Requirements. interpolate between charts to find the correct value. The break between the steep slope and culvert entrance should equal three to five times the mean rock diameter (or mattress thickness if gabions are used). Thickness.Riprap or gabions should be placed flush with the invert of a culvert. 2. shear stress shear for stress the gabion mattress for thickness of rock fil' the gabio n 4. see Appendix C.STEEP SLOPE GABION MATTRESSDESIGN 1. The design permissible shear stress. 3. Tp. the gabion mattress analyzed is not acceptable. For channel bottom widths in excess of 6 feet. =d = YdS ~ (5) If =d > TP.Td. size.15 ft/ft: d = 0.0 ft !=3 Find: Flow depth and mean riprap channel. Determine the permissible size from Chart 23. For given discharge and channel slope.15 ft/ft = 3. Example Problems Example 9: Determine the mean riprap size and flow Given: Q = 20 ft3/sec S = 0. Determine the permissible mattress from Chart 24. 54 I . given Q = 20 ft3/sec and S = 0. For intermediate channel width or side slopes.9 ft Example 10: Determine the mean riprap ~ size and flow depth for a steep gradient Given: Q = 30 ft3/sec S = 0. enter chart 19 to 22 for correc channel shape and determine flow depth.15 ft/ft =2ft !=3 Find: Flow depth and mean riprap Solution: Entering into chart depth for a steep gradient channel. size. will be the larger shear stress values determined in steps 2 and 3. 5. Calculate the maximum shear stress acting of the tw on the channel.75 ft 40 = 0. 16. follow the interpolation procedures given in steep slop riprap design procedure. 35 and Z = 4: A3/A4 = 0.70) = 1. for B = 4.70 = 0.2 problem is illustrated 55 in figure 24. 16. given d/B = 0.0 given Q = 30 ft3/sec and 17.15 ft/ft.81 ft 40 = 1.70 ft = 1. given Q = 20 ft3/sec and S = 0.20 ft/ft B = 2.60 ft Actual riprap size for 4:l *50 = (0.85 Actual flow depth for 4:l side slope.60/0.15 ft/ft. d = 0.Solution: (1) Enter into chart s = 0.9 ft (2) Interpolating for a 3.92 ft *50 = 1.2 ft (2) Enter into table 4. for B = 2.70 ft 40 = 0.85 x 0.0 given Q = 30 ft3/sec and 0.0 ft Z =4 Find: Flow depth and mean riprap Solution: (1) Enter into 40 chart size. x 1. .0 ft Example 11: Determine Given: the mean riprap size and flow depth for a steep gradient channel. d = 0. d= 16.1 ft Enter into chart S = 0. d = 0.0 ft bottom width gives.0 ft Use of the worksheet for this side slope. Q = 20 ft3/sec s = 0. d = 0.20 ft/ft. 12 stress =P stress for rockfill = 3. = 62.5 gabion worksheet lb/ft2 mattress for this = 0.55 ft shear = rdS stress = 4.1 =d problem 56 thick is < 4. (4) Use of the The = 4.5 TP UseTp thickness.55 x 0.12 ft/ft B = 2. for a 0.4 x 0. .12 ft/ft.8 lb/ft2 for = 4. in figure since 24.75-foot size from chart mattress 23.1 lb/ft2 from equation 5. thickness lb/ft2 design. lining Q = 10 ft3/sec S = 0.5 = 7p is illustrated acceptable.0 ft Z =3 D50 = 0. 0.Example Determine 12: the flow depth and required thickness of a gabion mattress and S = 0.75-foot = 4.5 ft Given: Find: Flow Solution: depth (1) From and gabion chart mattress 20 given Q = 10 ft3/sec d (2) Calculate the maximum 'd (3) Permissible Permissible from chart shear shear 24. d D50 (1) (1) (2) (3) (4) (5) 1.553 d =p Rock Table 4 d = tA3/Az)dj 40 Mattress Thickness 'p Mattress (6) (7) Charts Chart 19-22 23 13 (10) Chart 24 'P = the larger be -I_TP Problems 11 and Td must of = (d/di)D50i Figure 24. (2) . Worksheet for Example 57 12 (7) or (8) .5 4.1 w z A3/A.o L Rock Fill Size di (6) OS’ (3) (4) (5) 'p 'd=YdS (3) (9) (10) 1 4.s 1I * STATION: 12 TO STATION: DRAINAGE AREA: DESIGN FLOW: ACRES Q CHANNEL SLOPE (S) : CHANNEL DESCRIPTION: RIPRAP kwpie yzizjj t I) 2’ ” di D5Di 2 A3/A.7 Channel 0.Kw+ PROJECT: %&v.Worksheet for Steep DESIGNER: Slope Design DATE: E.6 REMARKS \.2 4 a85 0. Worksheet for Steep Slope Channel Design DATE: DESIGNER: PROJECT: STATION: TO STATION: DRAINAGE AREA: DESIGN FLOW: ACRES = Q CHANNEL SLOPE (S) ft3/sec : ft/ft CHANNEL DESCRIPTION: RIPRAP di D5Di Z A3/Az d D50 (1) (1) (2) (3) (4) (5) REMARKS GABION Rock Fill Size 1) 2) 3) 4) (5) di (6) Z A3/Az (2) (3) d =P Mattress (8) Charts 15-18 side slope (z:l) Table 4 d = tA3/Az)di (6) (7) Charts Chart = the 25. Worksheet for Steep 58 Slope 'd=YdS (9) (10) 19-22 23 larger D5D = Cd/di)D50i Figure =P Channel Design of (7) or (8) . 793 0.542 0.ooo 1.653 0.321 1.657 0.888 0.000 1.553 0.790 0.809 0.800 0.80 1.777 equation: '1 + 3(d/B) 1 + Lid/B) 59 0.30 1.782 0.000 1.000 1.222 1.000 1.000 1.823 0.550 0.800 0.291 1.30 0.625 0.608 0.714 0.733 0.544 0.804 0.60 1.000 1.307 1.400 1 Based on the following Aj/Az = 1.395 1.846 0.40 1.40 0.760 0.538 .678 0.700 0.352 1.000 1.1 d/B 0.815 0.540 0.661 0.000 1.142 1.833 0.650 0.644 0.386 1.083 1.368 1.00 1.853 0.000 1.783 0.647 0.250 1.727 0.391 1.000 1.000 1.000 1.640 0.000 0.90 1.578 0.812 0.60 0.785 0.688 0.90 2.20 0.596 0.50 1.10 0.378 1.666 0.361 1.381 1.556 0.Table 4.000 1.20 1.70 1.343 1.50 0.638 0.187 1.866 0.000 1.000 1 .10 1.00 1.000 1.642 0. Values of A3/Az for Selected Side Slopes and Depth to Bottom Width Ratios.000 1.571 0.80 0.561 0.636 0.272 1.779 0.565 0.672 0.647 0.333 1.796 0.928 0.000 1.547 0.680 0.70 0.787 0.780 0.586 0. Steep slope riprap design. S 40 40 35 35 30 ac 25 25 20 20 15 15 10 10 5 5 0 DEPTH. .RIPRAP MEAN DIAMETER. Chart 15. triangular d(f t) -channel 2 =3. (ft) 45 45 CHANNEL SLOPE. L 0 DISCHARGE.%SEC) Chart 16 4 i. cd Y .. 61 Q (FT. d(f t) B=4. Chart 17.(ft) I/ 25 25 20 20 15 15 10 10 5 5 0 DEPTH. s / MEAN DIAMETER. 2=3.RIPRAP ICHANNEL SLOPE. Steep slope tiptap design. I/ / . . S 30 25 20 0 DEPTH. 2=3.RIPRAP MEAN DIAMETER. Chart 18. Steep slope riprap design. (ftj 50 45 . 4s 40 40 35 CHANNEL SLOPE. . d(f t) B=6. 25 d(f CitttJt) tress.CHANNEL SLOPE3 SLOPE. triangular channel. . 1. 2 = 3.25 1.S 15 .5 ‘0 1.00 .75 DEPTH. Steep d(ft) 1.so 4s CHANNEL SLOPE. DEPTH.so .00 1. Chart 20.50 . B=2. Z= 3.25 slope gabion mattress. S 40 15 10 S 0 0 .7s 1. f .Chart -- 21 66 - 4. 1.CHANNEL SLOPE. Z= 3.50 . S .oo 1.75 . B ‘6. Chart 22. Steep slope 1 .25 d(ft) gabion mattress.50 DEPTH. oo 0. THICKNESS 1 .50 ROCK Chart Chart 23.25 gabion mattress 1. 1.25 0.25 DIAMETER shear stress fill size.75 SIZE Permissi de versus r xk MEAN 1.5 (ft) for gabion mattress 24 15 10 7P Ib/ft* 5 0 0 0.50 MATTRESS Cha’rt 24.75 0.f .Chart 23 10 TP Ib/ft* 5 0 0. 1 .oo (ft) Permissible shear stress for versus mattress thickness. 68 1.25 0. A solution is to provide a nonvegetative low-flow channel lining such as concrete or riprap. The dimensions of the low-flow channel are sufficient to carry frequent low flows but only a small portion of the design flow.VI. is important that the so that adequate protection is completely protected. A temporary lining should be used adjacent to the low-flow channel to provide erosion protection until the vegetative lining is well established. For determination of equivalent roughness. the channel area is divided into two parts of which the wetted perimeters and Manning's n values of the lowflow section and channel sides are known. In the case of composite channel linings with vegetation on the banks. 69 . The maximum shear on the side of the channel is given by the following equation: TS where chapter K1 is IV) and It bottom bottom distance (15) = Kl~d a function of channel geometry and is given 'Cd is the shear stress at maximum depth. The remainder of the channel is covered with vegetation. chapter III) is such that the maximum shear stress on the sides of the channel is significantly less than on the channel bottom. In erodible soils. erosion may occur near the boundary of the two linings. up the side slope. for various applications of two channel linings. Special Considerations When two lining materials with significantly different roughness values are adjacent to each other. causing additional erosion. and can result in a safety hazard. bed is the in chart 13 (in lining material cover the entire channel provided. Kc. Gullys weaken a vegetative lining during gully at the bottom of the channel. this leads to the formation of a small merged vegetation. Erosion of the weaker lining material may damage the lining as a whole. determining the equivalent roughness coefficient. These two areas of the channel are Chart 25 provides a means of then assumed to have the same mean velocity. COMPOSITE LINING DESIGN Composite linings protect the bed of a channel against the higher shear stress occurring in that portion of the channel. The distribution of shear stress in a trapezoidal channel section (see figure 18. Another important use of composite linings are in vegetative lined chanThese low flows will usually kill the subnels that have frequent low flows. higher flows. this problem can occur in the early stages of vegetative establishment. To guarantee that the channel bed lining should be extended a small Computation of flow conditions in a composite channel requires the use of an equivalent Manning's n value for the entire perimeter of the channel. This allows for a channel lining material to be used on the side slopes that has a lower permissible shear stress that the lining material used for the bottom of the channel. (Table Determine Manning's n for each lining type. linings and charts 5 to 9 for vegetative linings.ow depth. Determine the permissible (see table 2) shear stress 2.Design Procedure COMPOSITELINING DESIGN PROCEDURE The procedure for composite lining designs consists of the followir steps. nZ/nl. perimeter. difference is greater than 0. n. for both lining types. Determine the shear stress at maximum depth. wetted Kc. di. Determine d. for PR . If Td. R. 3 for nonvegetatiy n values. 7. Td and Ts. Ts Manning's with calculated flow depth. T for each of the channel linings. and the wetted perimeter. Determine the hydraulic radius. di. Compute the ratio of low-flow wetted perimeter. from chart 25. 10. and the shear stress tl I 'd = rdS and Ts = Kl =d where KI is from chart 11. to tl toti Calculate tl n = Kc nI where nI = Manning's channel n flow depth. Determine effective the depth of flow. Compare estimated fl.1 ft. Compare the shear stresses. 8. to the permissible shear stress. Estimate 3. d. Tp. the channel side slopes. entire channel section (chart 4 or equations in appendix A). P. repeat steps 3 through 8. (15) 13. Compute the ratio 5. If 'Id or Ts is greater the Tp fl t/k respective lining. of rougher to smoother Manning's channel a compound lining factor. 1. for smoother lining.) 4. P. using the effective 9. a different combination of linings should be ev' luated. 70 . (P./P). 6. Manning's n from. 3.02 ft/ft Trapezoidal channel shape Z =3 Concrete low-flow channel. wide C VEGETATION CONCRETE F.0/0.00 lb/ft2 . and concrete is a nonerodible.0 ft CLASS concrete Find: lining.0 x 1.The design procedure is demonstrated in the following worksheet at the end of this chapter (figure 28) is provided the compound lining design procedure computations. Solution: (1) Permissible shear stress for Class C vegetation. (2) Flow depth in channel. rigid lining. example. (2) Initial depth is estimated at 1.0 ft3/sec s= 0. given d/B = 0.igure 26.33 R/d = 0. and vegetation Compound Lining (1) Effective Manning's n.0 ft (3) From chart 4.0 ft2 = 6.64 R= A/Bd = A= P = = 0. (3) Suitability of channel lining LOW FLOW CHANNEL Example.0 = 6.64 ft 71 ~~ = 1.0 A/R 9. for carrying The out Example Problem Example 13: Determine Given: the channel design for a composite Q = 10.64 2.4 ft x 3.0 2. materials. 87 72 given Qn = 0. given PR/P = 0. From chart 0.h.36 7 for Class C vegetation.rt 25.013 = 0. n2 = 0.4 (5) From chart 25.072 (6) From chart 3 for S = 0. n2 = 0.56 (4) From chart (5) 4.56 = 8.84 4.72 and B = 3.02.The concrete the sketch.083/0. I .28 d = 0.64/0.095.0 n = 5.65 and B = 3.3. d/B = 0.4 = 0. therefore repeat steps 3 through 6. .3 ft 3. R/d = R= A/Bd = = F = Pa/P = depth of flow is 0.29 d = 0. nl = 0.065 KC 3 for S = 0.o.013 n2& = 0. lining provides the low-flow channel.083 From table 3 for concrete. = 5.0 x 0. give 0.013 1 = 6.64 ft2 4.0/8.095/0.013 = 7. as given 5 Pa = 3. (3) l$ _ryy.3 [.0/9. n2/n1 = 0.36 and n2/nl = 7.32 and n2/nl = 6.0 Pa/P = 3. given P&/P = 0.32 (4) From chart 7 for Class C vegetation.84 ft (6) From chart The difference between calculated depth and estimated depth i greater than 0.013 = 0.d .66 1.020. . d/B = 0. n = 5:5 x 0.3 = 0. given Qn = 0.1 feet.84 ft.4. 1 feet. so the lining is acceptable.The calculated and previous The results are.09 = 0. Kl.87 x 0.072 d" = 0. is determined given Z = 3 and B/d = 3. = 0.171 The shear stress. Td = YdS = 62.87 ft . values of depth are within 0.87 x 1.02 = 1.95 lb/f@ (8) The maximum shear stress on the channel side slopes permissible.4 x 0. as K1 = 0.45.87 ‘IS is deter- from chart 13 = 0. TS on the sides of the channel = K1 Td where the shear stress ratio. 73 is less than .09 lb/ftz The maximum shear stress mined from equation 15. at maximum depth from equation 5. Worksheet for Compound Lining Design DATE: DESIGNER: PROJECT: TO STATION: STATION: ACRES DRAINAGE AREA: DESIGN FLOW: = Q ft3/sec DESIGN FLOW FOR TEMPORARY LINING: CHANNEL SLOPE I (S) = Q ft3/sec ft/ft : CHANNEL DESCRIPTION: Lining I Type . ~~ for Lining channels lowflow sides Design I t . (3) Lowflow Side (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) Table 2 Non-vegetative linings. Worksheet (12) (13) for 74 Compound Chart 25 n = K." n (2) P. trapezoidal channels Ratio of rougher to smoother n Total channel wetted perimeter Figure 27.nl Chart 3. charts 5-g Lowflow channel wetted perimeter Flow depth. trapezoidal 'd = vds 'rd must be 2 TP for Chart 13 Ts = Kl'ld 's must be 1. table 3 Vegetative linings. estimate Chart 4. 0' Y di L (4) i-0 R (5) (3) (4) (5) (6) (7) n A.072 Table 2 Non-vegetative linings.O$F.oQ5 F. CoNcveti - gw33s-dsssc 1.3 d Xd Kl "s (10) (11) (12) (13) a84 e - - REMARKS $44.:I for 75 Example Chart 25 n = K.4 -84 . trapezoidal 'd = rds Td must be L rp for Chart 13 = Kl'd ‘S ~~ must be 2 'tp for Problem 13 channels lowflow sides .06S -64 6.r .00' 3f3 P (3f (Z.Worksheet for Compound DESIGNER: Lining Design DATE: EXQMP~ PROJECT: Pmblew \3 STATION: TO STATION: DRAINAGE AREA: DESIGN FLOW: ACRES = Q 10 ft3/sec DESIGN FLOW FOR TEMPORARY LINING: CHANNEL SLOPE (S) : o*cQ Q ft3/sec = ft/ft CHANNEL DESCRIPTION:' 73 Lining Type Lowflow Side =P (1). Worksheet (8) (9) (10) (11) [.nl Chart 3.w' couc 1. table 3 Vegetative linings. charts 5-9 Lowflow channel wetted perimeter Flow depth.&L .013 3 . . . trapezoidal channels Ratio of rougher to smoother n Total channel wetted perimeter Figure 28. . estimate Chart 4.56 (1) (2) "2 "1 (6) 7. Roughness factor for compound 76 channel linings.5 PJ /P Chart 25.) 1 ’s 2’3 I “1 = = “2 PA = kwetted roughness for Smoother rOUghne88 for rougher wetted Perimeter perimeter lining for for lining entire low flow channel channel 2. Chart 25 Y”I”“I”“““’ i I Based Kc= on I the /Pt(l-PII fOIlOWing eqUatiOn: /PNn2/n.. . APPENDIX A EQUATIONS FOR VARIOUS CHANNEL GEOMETRIES T -I A = Zd? P=2ddZ’+l T=2dZ V-SHAPE A =LTd 3 P = 1 dm+ 2 4d+ c 16d T +T . T= 1. Equations TRAPEZOIDAL for Various 77 Channel Geometries. .5A d PARABOLIC A = id + Zd2 P=B+2d-/z T=B+2dZ Figure 29. 2 IF d >l/Z. 1 IF d Ii/Z. . THEN: NO.I CT---71 4 1 4 2 CASES NO.‘THEN: A=$Z + 4@) + Zc-+)’ P=2Z lne V-SHAPE WITH ROUNDED BOTTOM Figure 29. Equations for Various 78 Channel Geometries (continued). These values are based on an analysis of data collected by McWhorter et al. can be seen that for values of relative roughness less than 10.15) for the Department of Transportation. and the empirical coefficients. Over this range. and Thibodeaux (14. (1) The (16) (R/k. b R kS 9 = = = = = = + b log linings can be accuralaw. With grasses. there is significant variation in the n value. a and b. roughness element height . the relative roughness will vary depending on the bending of the vegetation with the degree of bending being a function of the stiffness of the 79 t * . empirical coefficients. the n value varies about 20 percent. for different lining material are given in table 5. shear velocity which is (gRS)05.)1 mean channel velocity. Values of k. hydraulic radius. It The relative roughness of vegetative channel linings depends on physical characteristics of the grass as well as the shear stress exerted on the grass. [a where V V* a.(g) Manning's equation (equation Manning's roughness coefficient resulting equation is: 1) and equation n in terms of 16 can be combined to the relative roughness. The coefficients for riprap we-%veloped by Blodgett and McConaughy (19) and the coefficients for vegetation are from work by Kouwen et al.APPENDIX B DEVELOPMENTOF DESIGN CHARTSAND PROCEDURES Resistance tely form Equations Resistance to flow in open channels with flexible described using the universal-velocity-distribution of the resulting equation is: V = V. to the one-sixth power in Figure 29 shows the behavior of Manning's n versus relative roughness. give The (171 The order n to value is make both divided sides of by the roughness height the equation dimensionless. and acceleration due to grav ity. Flow conditions in small to moderate sized channels will typically fall in the range of relative roughness from 10 to 100. 74 8.07 0.004 0.66 2.12 0.12 3.16 0.35 0.13 4 0.035 1.00 Straw Net 0.33 20 61 10 50 1.0 91 F D 0.73 8.25 5.72 7.038 1. h Retardance Class (ft) Vegetation.cm) @ ft2) A 3.96 8.012 725 80 (Newton @ m2) 300 20 0.98 0.04 Mesh Fiberglass Roving 0.66 0.12 E 0. kS Lining Material (ft) (cm) b a Woven Paper 0.83 0.42 5.11 3.65 7.00 Jute 0.065 1.05 0.13 2.0 0.23 With Curled 'Synthetic Wood Mat Mat Riprap 050 19 equation Vegetation Table 6.2 0.10 0. Empirical Coefficients for Resistance Equation. Relative Roughness Parameters for Stiffness ME1 Average Height.Table 5.005 .73 8. (lb (.23 0.5 0. 03 1.0 4.05 - 0.07 c -w A I 0. Roughness - --- Net . Figure 30.0 2.1 0.0 s.04 - 0.0 3.2 I I ]II 1 Riprap 2 Jute Net 3 Enkamat 4 Excelsior 5 Straw With 1 -- 0.- 0. 0.08 --- 5 $ 0.0 R/k.09 0. n Versus Relative Manning's for Selected Lining Types.08 W * (D . and = stiffness factor. the Manning's roughness coefficient can described as a function of hydraulic radius and mean tractive force. are given in table 6. ficient is substantial. linings C is 19. = ave. T resulting equation is: i n = . The relative roughness for grasses in classifications A through E is typical1 In this range. I roughness.vegetation and the shear stress tion is given by: where l/4 conditions. shear stress.. e e p (19) C + 19. ML Values of h and known as retardance Roughness height /h]1*5g for vegeta (18) ME1 for various classifications of vegetative classifications.(b) 2 = 0.97 log (R104 Suo4) where tion.14 CC+ h = average height of vegetation.8 hoo6 ME1'Oo4 1 and depends on the class of veget Design charts for determining Manning's n for vegetative charm 1 were developed by plotting values given by equation 19. and it is not acceptable to u.se only an average valu By combining equations 17 and 18.97 log (44. the variation in the Manning's roughness toe less than 10. % 82 I . The Bathurst resistance equation is used to predict hydraulic conditions in steep gradient channels and the factor of safety method is used to assess riprap stability.APPENDIX C DEVELOPMENTOF STEEP GRADIENT DESIGN CHARTS AND PROCEDURES General The design of riprap for steep gradient channels presents special problems. creating a very complex flow condition. Bathurst Resistance Equation Most of the flow resistance in channels with large-scale roughness is derived from the form drag of the roughness elements and the distortion of the flow as it passes around roughness elements. For Reynolds numbers in excess of 2 x 105. the Reynolds effect on resistance remains constant. 83 . The work shows that for Reynolds numbers in the range of 4 x 104 to 2 x 105. i. Bathurst's experimental work quantified these relationships in a semiempirical fashion. a flow resistance equation for these conditions has to account for skin friction and form drag. On steep gradients. Froude number (the ratio of inertial forces to gravitational forces). A brief discussion of both methods is given in this appendix and the assumptions used in developing the design procedures are presented. The development of design procedures for this manual has. resistance is likely to fall significantly as Reynolds number increases. but those related to standing waves are important. When roughness elements protrude through the free surface. Consequently. resistance increases significantly due to Froude number effects..ap elements often protrude from the flow.e. For the channel as a whole. therefore. The ripr. the riprap size required to stabilize the channel is often of the same order of magnitude as the depth of flow. Laboratory studies and field measurements (20) of steep gradient channels have shown that additional factors need to be considered when computing hydraulic conditions and riprap stability. free-surface drag decreases as the Froude number and relative submergence increase. Froude number effects related to free-surface drag are small. the flow resistance will vary with relative roughness area. and Reynolds number (the ratio of inertial forces to viscous forces). roughness geometry. standing waves. and free-surface drag. hydraulic jumps. Because of the shallow depths of flow and the large size of the roughness elements. Once the elements are submerged. been based on equations that are more general in nature and account directly for several additional forces affecting riprap stability. 755/b) (21) Fr) 0.(Fr) n form bl. = constants a.mensionless -(din/6) V K where' = v* = d= 9 = = F. where: distribution (251 the giving log standard a c value 84 S properties. and = 13. c The parameter. y50 = mean value of the distribution of median axes of a roughness element. effective bed. b= parameter describing the effective The parameter concentration and ship is given by: b describes the relationship relative submergence of the the average and roughness between roughness of the long concentration. roughne !I and vari eS of the roughness size gradation. (T.f velocity (Fr) x divided the Bathurst f (REG) n by the equation is: (20) f (CG) n x shear of Froude number.814. This S50 = mean of elements. element geometry. roughness by the following equations: log = (7 velocity.(CG) where = (.118 A y50 (22) -b f. functions are given f. and channel geometry. C = 0. Manning's roughness coefficient.182. is assumed to . with respect to the short and varying c.492 f.I (23) T= channel topwidth. is a function the bed-material axis lengths of with bed material the distribution of riprap a value gradations of 0. mean flow depth.fj481s-O*134 For standard constant at roughne relation (24) b = a Id 1' s50 where and deviation of 0.(REG) of (gdS)O5. Froude number.The general d.434 charm (0.025(T/Y50) 0. acceleration due to gravity. = REG = CG = The geometry mean . roughness element geometry. 1/c = 1.(21) The resulting set of equations are used to compute the factor of safety: case tan9 (29) SF = . describe the stability of a riprap element include: cx = angle of the channel bed slope. plane of the side slope.. The contact point. a. respectively. is therefore substituted for S50 and Y50 tions.).557 .175 (-y50 (26) T) In solving equation 20 for use with this manual. Figure 30 illustrates an individual eleThe geometric terms required to completely ment and the forces acting on it. the drag force acting in the direction of flow (Fd). is a function of channel width and bed material cross stream direction. parameters. and is defined as: 0. and their 6 6 = angles between the two vectors: resultant in the. Riprap Stability The stability of riprap is determined by analyzing the forces acting on an individual riprap element and calculating the factor of safety against its movements. it is assumed that the axes of a riprap element are approximately equal for standard riprap gradaThe mean diameter. !L2 ws case SF = !tl'ws sine cos@ + E3 td cos6 + !$ tL where SF = safety of moments resisting (28) factor. analyzed by calculating the moments causing the particle to roll about the c. t an+ + sin0 cosf3 -1 cosa b = tan 2 sine + sina n tan+ 85 . and the lift force acting to lift the particle off the bed (FL). D50.size in the The parameter. = angle of the channel side slope. and i = angle of repose for the riprap. with an adjacent riprap element as shown in figure 30. The forces acting on a riprap element are its weight (W. weight and drag. its stability is. equation describing the equilibrium of the particle is: JL2ws case = El Ws sine cosB + R3 Fd cos6 + R4 FL The factor of safety against movement is the ratio This yields: motion over the moments causing motion. As the element will tend to roll rather than slide. Evaluation of the forces and moment arms for equation 28 involves several assumptions and a complete derivation is given in Simons and Senturk.. Hydraulic ws cos Element 0 A -A Forces Acting on a Riprap Element. 1. SECTION Figure 31. sin 8 cos TO SIDE SLOPE B C 4 w 1.Top of Bank Riprap Element Water Surface Bed Slope VIEW NORMAL W. 86 + . Riprap . equal to 0. F* was equal to 0. This value was used in developing the design charts of this manual (charts 15 through 18). from chart 13.047.5 is used. Based on this work and Reynolds numbers encountered in steep gradient channels. the design procedure sets F. Solution Procedure The solution procedure using the Bathurst resistance equation and factorof-safety approach to riprap stability is outlined in the flow chart given in figure 31.15.n and where = ‘S I-* (ys-y n' = 7-l 1 + sin (31) ) D50 (01 + fd (32) 2 Ts = side slope shear stress. The side slope shear stress T = K1 ~~ can be computed as: (33) S can be obtained Kl from chart 12. YS = specific weight of water. 87 . rl = stability number. critical shear stress. D50Y= median diameter of the riprap. and n' = side slope stability number. L = dimensionless = specific weight of the rock. A factor of safety of 1. Recent studies (22) have shown F* to take onmuch larger values for large-diameter particles'-in flow conditions having a high Reynolds number. The angle of repose 4 may be obtained In the derivation given in Simons and Senturk (211. . Smaller . Steep 88 Slope Design Procedure.Determine Design Q + Compute Safety Factor Choose Larger + Yes D50 No Choose Figure 32. resistant to weathering and to water action. durable. The sources from which the stone will be obtained shall be selected well in advance of the time when the stone will be required in the work. Stone used for riprap shall be hard. shale and organic material. and shall meet the gradation Neither breadth nor thickness of a single requirements specified. Rock riprap. weight of the stone shall be 155 pounds per cubic foot as computed by multiplying the specific gravity (bulk-saturated-surface-dry basis. a well in materials and side this and slopes specification performing all work of channels. The acceptability of the stone will be determined by service records and/or by suitable tests. Riprap consists of stone Rock riprap.APPENDIX D SUGGESTEDGUIDE SPECIFICATIONS the The Specifications and should designer. ticular quarry site shall not be construed as constituting the approval of all rock fragments taken from that quarry. of riprap The types a. suitable samples of stone shall be taken in the presence of the engineer at least 25 days in advance of the time when the placing of riprap is The approval of some rock fragments from a parexpected to begin. Rounded stone or stone should be less than one-third its length. 89 to disintegration be subjected as stated in abrasive action abrasion test in the from will be the spe- from material Los Angeles . When the transported riprap must withstand the by the stream. spoil.3 pounds per cubic foot. or as are: dumped in place graded mass with Gravel placed on filter graded mass with a minimum of blanket voids. free from overburden. on a filter a minimum of or prepared Materials a. angular in shape. in this appendix are presented for the information be modified as required for each individual design. blanket or prepared slope to form a well voids. The minimum Shale and stone with shale seams are not acceptable. resistance the type of exposure to which the stone will determined by any or all of the following tests cial provisions: 1. of RIPRAP Description This work consists of furnishing necessary to place riprap on bottoms directed by the engineer. boulders will not be accepted unless authorized by special provisions. b. In the absence of service records. AASHO Test T 85) times 62. Gravel slope channel to form included lining. If testing is required. Control of gradation will be by visual inspection. and other objectionable materials and be dressed to trees. flat. General. Mechanical equipment. toe trench as shown on the plans shall be dug and maintained until the riprap is placed. The sample at the construction site may be a part of the finished riprap covering. the stone shall percentage loss of not more than 40 after 500 revolutions. the stone should have a loss not exceeding 10 percent after 12 cycles of freezing and thawing. stumps. When the abrasion test in Angeles machine (AASHO Test T 96) is used. All soft or spongy material shall be removed to the depth shown on the plans or as directed by the engineer and replaced Filled areas will be compacted and a with approved native material. Requirements Gravel riprap shall consist of gravel or thickness and gradations shown on project comprising the riprap shall be composed of reasonably free of thin. Stones smaller than the specified 10 percent size and spalls will not be permitted in an amount exceeding 10 percent by weight of each load. All . Gravel channel lining. smooth surface. crushed rock of the drawings. ~_I- /-- Slopes--to be protected by riprap shall be free of brush. The type of riprap specified will be placed in accordance with these specifications as modified by the special provisions. When the freezing and thawing test (AASHO Test 103 for ledge rock procedure A) is used as a guide to resistance to weathering. subject to freezing the sulfate soundness sodium sulfate) shall exceeding 10 percent the Los have a 2. rock using loss not 5 cycles. . or where the stone is exposed to test (AASHO Test T 104 for ledge be used. 90 ~ . meeting the gradation specified. In locations salt water. a sorting site. b. or elongated contain organic matter. Protection for structured foundations shall be provided as early as the foundation construction permits.machine shall also be used. Any difference of opinion between the engineer and the contractor shall be resolved by dumping and checking the gradation of two random truck loads of stone.material tough durable particles particles and shall not Construction a. These samples shall be used as a frequent reference for judging the gradation of the riprap supplied. Each load of riprap shall be reasonably well graded from the smallest to the maximum size specified. The area to be protected shall be cleared of waste materials and the -surfaces to be protected prepared as shown on the plans. The contractor shall provide two samples of rock of at least 5 tons each. and labor needed to assist in checking gradation shall be provided by the contractor at no additional cost to the State. The other sample shall be provided at the quarry. Stones shall have a with the sulfate test after 3. and any material displaced by any cause shall be replaced to the lines and grades shown on the plans at no additional cost to the State. The entire mass of stone shall be placed so as to be in conformance with the lines. pared slope or area. b. and the contractor may be required to remove and dispose of the excess riprap without cost to the State. or by similar methods likely to cause segregation. and thicknesses shown on the plans. the riprap protection shall be placed in conjunction with the construction of the embankment with only sufficient lag in construction of the> riprap protection as may be necessary to allow for proper construction of the portion of the embankment protected and to prevent mixture of embankment and riprap. of specified thickness and extent. work shall on the consist Rock riprap. The larger stones shall be well distributed and the entire mass of stone shall conform to the gradation specified by the engineer. Placing of riprap in layers. 91 . for riprap shall be placed thickness of and methods on the pre- Measurement for Payment The quantity of riprap to be paid for. segregation. as shown on the plans. shall be measured by the number of cubic yards as computed from surface measurements parallel to the riprap surface and thickness measured normal to the riprap surface. Gravel channel lining. Riprap placed outside the specified limits will not be measured or paid for. Stone for riprap shall be placed on the prepared slope or area in a manner which will produce a reasonably well-graded mass of stone with the minimum practicable percentage of voids.When shown on the plans. When riprap and filter material the layers shall be increased shall be used that will minimize c. fabric shall be with foundation The contractor shall maintain the riprap until all contract has been completed and accepted. grades. The contractor shall maintain the riprap protection until accepted. All material going into riprap protection shall be so placed and distributed so that there will be no large accumulations of either the larger or smaller sizes of stone. will not be permitted. by mechanical equipment may be required to the extent necessary to secure the results specified. Gravel are dumped under water. in place and accepted. Maintenance of the repair of areas where damaged by any cause. a filter blanket or filter placed on the prepared slope or area to be provided protection as specified before the stone is placed. Riprap shall be placed to its full course thickness at one operation and in such a manner as to avoid displacing the underlying material. or by dumping into chutes.ial are placed in their Hand placing or rearranging of individual stones proper proportions. Unless otherwise authorized by the engineer. It is the intent of these specifications to produce a fairly compact riprap protection in which all sizes of mater. the preparation of the subgrade. the grouting when required. 92 cubic yard and for furnishing the placing of incidental to I . the riprap. tools. and all other work finished construction in accordance with these specifications. and labor.Basis of Payment Quantities shall be paid for at the contract unit price per shown in the bid schedule which price shall be full compensation all material. Stone used shall be well graded and the smallest dimension of 70. by weight.WIRE ENCLOSEDRIPRAP Description This work. protective coat over the area specified. and shall be of . Details of construction may differ depending upon the degree of exposure and the service. Wire enclosed segments shall be hand.5:l and steeper. Perimeter edges of wire enclosed units are to be securely selvedged or bound so that the joints formed by tying the selvedges have approximately the same strength as the body of the mesh. measured normal to the slope. shall exceed the wire mesh opening. whether used for revetment or used as a toe protection for the other types of riprap.or machine-formed to the dimensions shown on the plans. and filled to provide a uniform. and anchored to the slope. Mattresses and baskets on channel side slopes should be tied to the banks by anchor stakes driven 4 feet into tight soil (clay) and 6 feet into loose soil (sand). laced.5:1. the following is the minimum spacing: Stakes every 6 feet along and down the slope for slopes 2. however. Channel linings should be tied to the channel banks with wire-enclosed riprap counterforts at least every 12 feet. Wire mesh shall be galvanized woven fencing conforming to the specifications for fence fabric. The maximum size of stone. Construction Requirements Construction requirements shall meet those given for rock riprap.the gage and dimensions shown on the plans. Wire-enclosed units shall be tied to its neighbors along all contacting edges at l-foot intervals in order to form a continuous connecting structure. Materials Material requirements shall meet those given for riprap.. Wire enclosed riprap consists of mats or baskets fabricated from wire mesh. Ties and lacing wire shall be No. so that the stakes are an integral part of the mattress or basket. Counterforts should be keyed at least 12 inches into the existing banks with slope mattress or basket linings and should be keyed at least 3 feet by turning the counterfort endwise when the lining is designed to serve as a retaining wall. The exact maximum spacing of the stakes depends upon the configuration of the mattress or basket. and every 9 feet along and down the slope for slopes flatter than 2. These units shall be placed. dense. shall not exceed the mat or basket thickness. 9 gage galvanized unless otherwise specified. The anchor stakes should be located at the inside corners of mattress or basket diaphragms along an upslope (highest) wall. connected together. except for size and gradation of stone.will consist of furnishing all materials and performing all work necessary to place wire enclosed riprap on bottoms and side slopes of channels or as directed by the engineer. 93 / . percent of stone. filled with stone. the preparation of the subgrade. which price shall be full compensation for tools. cified limits will not be measured or paid for. and all other work incidental to finished construction specifications. and labor. 94 yar fur th i i I . accordance with these be paid for at the contract unit price per square schedule. and the contractor may b required to remove and dispose of the excess riprap without cost to the State. Basis of Payment I Quantities shall and shown in the bid nishing all material.Measurement for Payment i The quantity of wire-enclosed riprap of specified thickness and extent place and accepted. shall be measured by the number of square yards obtained b Riprap placed outside the spe measurements parallel to the riprap surface. placing of the stone. 1 foot back from the crown and at the bottom of the slope. shall be measured by the square yard of finished surface. Rolls shall overlap 4 inches. they should be applied immediately before laying the fabric. completely in place and accepted. Measurement for Payment The quantity of woven paper net. ditches. Woven paper net placed outside the spe& cified limits will not be measured or paid for and the contractor may be required to remove or dispose of the excess without cost to the State. interwoven with paper strips. No allowance will be made for overlap. Woven paper net shall be draped rather than stretched across the surface. Basis of Payment Quantities shall be paid for at the contract unit price per square yard which price shall be full compensation for furnishing a71 materials. including staples. the placing of the woven paper net. materials and all work necessary to control on roadway. or slo- Materials Materials shall consist of knitted plastic net. Woven paper net shall be applied on slopes with the fabric running vertical from the top of the slope. In drainages. the preparation of the subgrade. Staples shall be 6 inches and 12 inches in length. The contractor shall maintain the fabric blanket until all work on the contract has been completed and accepted. and labor. Heavy gauge staples shall secure the fabric at g-inch intervals along the edges and overlaps and at 3-foot intervals down the center of the fabric roll.WOVENPAPER NET Description This work shall consist of furnishing install woven paper net fabric for erosion pes. The yarn shall be of photodegradable synthetic types and the paper shall be biodegradable. Construction Requirements Woven paper net shall be placed on the prepared slope or seedbed area which has been prepared and leveled according to various other sections in these specifications. Maintenance shall consist of the repair of areas where damaged by any cause. or as directed by the engineer. and remulched as directed. reseeded. 95 . The fabric shall be secured and buried in a 4-inch trench. All damaged areas shall be repaired to reestablish the condition and grade of the soil prior to application of the covering and---shall be refertilized. woven paper net shall be applied in the direction of the water flow. tools. If seeding and fertilizer are in the provisions. and composed of high carbon iron. and all other work incidental to finished construction in accordance with these specifications. The portion surfac the jute remaining above ground is unfolded and laid flat on the soil Check slots will be spaced so that one check slot or junction slot occu Overlaps which run down the slope. the trench shall closed. T A piece of jute. net will have a row of staples down the center as well as along each edg interval Check slots and junction slots will be stapled across at 6-inch . thl upslope piece should be brought over the buried end of the second roll so tha. immediately aftei material shall bl stretching. as specified of weave oi be of i than 1. outsi without each 50 feet of slope. loosely twisted construction having an average twist of not less turns per inch and shall not vary in thickness by more than one-half mal diameter. made. single jute yarn.t its nor90-pounc cloth yard 6. with in + 5 percent length. .JUTE NET Description This essary to engineer. Each width of ju edges and centers shall be stapled on 2-foot intervals.. The yarn shall unbleached. After the jute is buried. is folded lengthwise. and 12 inches by the engineer. work consists install jute of furnishing net on roadway materials ditches or and performing all work nec. fold is placed in the trench and the trench is tamped closed. slopes or as directed by the ? Materials Jute net shall consist of heavy mesh of a uniform open plain smolder-resistant. The a narrow trench ( be firmly tampet In cases where one roll of jute mesh ends and a second roll starts. The jute net shall be furnished in approximately rolled strips and shall meet the following requirements: Length Width Weight bon Staples iron or Construction approximately 75 yards 48 inches + 1 inch 78 warp en% per width 41 weft ends per yard 1.22 pounds per linear shall be 3. Where two or more width an overlap of at least 4 inches must b of jute net are applied side by side. and composed of high car Requirements The blankets shall be placed in designated locations The seeding and mulching operations have been completed. A narro trench should be dug across the slope perpendicular to the direction of flo cut the same length as the trench. s e e . i 96 I . applied smoothly but loosely to the soil surface without upslope end of each piece of jute net shall be buried in inches deep. there is a 12-inch overlap to form a junction slot. e f . Check slots should be made before the jute net is rolled out. 97 price per square yard all materials. tools. including staples. Mat placed outside the specified limits will not be measured or paid for. the preparation of the subgrade. and the contractor may be required to remove and dispose of the excess mat without cost to the State. has been completed and accepted. Basis of Payment Quantities shall be paid for at the contract unit which price shall be full compensation for furnishing and labor. and accordance with these . Maintenance shall consist of the repair of areas where damaged by any cause. The contractor shall maintain the jute mesh until all work on the contract. the placing all other work incidental to finished construction in specifications. No allowance will be made for overlap. All damaged areas shall be repaired to reestablish the condition and grade of the soil prior to application of the covering and shall be refertilized. reseeded and remulched as directed. Measurement of Payment The quantity of jute net. soil. completely in place and accepted. composed of The jute net must be spread evenly and smoothly and be in contact with the seeded area at all points. use 3-inch sharp-pointed fence-type staples.For extra hardened hard steel. of the jute net. shall be measured by the square yard of finished surface. The material shall contain no petroleum solvents or othfer agents known to be toxic to plant or animal life.00035-0. percent Package Weight. The roving shall be wound into a cylindrical package approximately 1 foot high in such a manner that the roving can be continuously fed from the center of the package through an ejector driven my compressed air and expanded into a mat of glass fibers on the soil surface. area wit in I The fiberglass roving shall be spread uniformly over the designated a ea er to form a random mat of continuous glass fibers at the rate of 0. inch (Trade Designation-G) Yd/lb of Sand Yd/lb of Rove Organic content. or like deleterious substaices. Liquid asphaltic AASHTO M81.000-14.25 pounds cubic yard. This rate may be varied as directed by the engineer.000 210-230 0. lb to the types. detailed requirements: shall conform the designated The fiberglass Limits Construction The 24 hours 56-64 184-234 maximum requirements grades. coated with a chrome-complex sizing compound. The material shall be formed from continuous fibers drawn from molten glass. I General requirements. b. Detailed to these materials and Ml41 for requirements.over the have been designated completed. roving of confo shall m r Property Strands/Rove Fibers/Strand Fiber Diameter. collected into strands and lightly bound together into roving without the use of clay.FIBERGLASS ROVING I Description This work consists of necessary to install fiberglass directed by the engineer.75 30-35 Test Method End Count ASTM ASTM ASTM ASTM ASTM D D D D D 578 578 578 578 578 Requirements fiberglass after the roving shall normal seeding be applied operations . or Materials a. 98 : . furnishing roving materials on roadway and performing all ditches or slopes. starch.0004 13. I .and 0. M82. the placing of the roving. Instructions for slope and ditch protection may be stipulated by the engineer to fit the field conditions encountered. the preparation of the subgrade. This rate may be varied as directed by the engineer. reseeded and remulched as directed. of Payment Quantities shall be paid for at the contract unit price per pound and shown in the bid schedule. The upgrade end of the lining shall be buried to a depth of 1 foot to prevent undermining.25 gallon per square yard. The contractor shall maintain the roving until all work on the contract has been completed and accepted. Maintenance shall consist of the repair of areas where damaged by any cause. Measurement for Payment Fiberglass roving will be measured by the pound. All damaged areas shall be repaired to reestablish the condition and grade of the soil prior to application of the covering and shall be refertilized. tools. and labor. Roving specified limits will not be paid for and the contractor remove and dispose of the excess roving without cost to the Basis the quantity to be placed outside the may be required to State. and all other work incidental to finished construction in accordance with these specifications. and measured will be that actually used on the project. .The fiberglass roving shall be anchored to the ground with the asphaltic materials applied uniformly over the glass fibers at the rate of 0. which price shall be full compensation for furnishing all materials. aiierage roll yd2 roll Pins and staples shall be made of high carbon iron wire 0. All damaged areas shall be repaired to reestablish the condition and grade of the soil prior to application of the covering and shall be refertilized. "U" shaped staples shall have legs 8 inches long and a l-inch crown. furnishing wood mat on materials roadway and performing all ditches or slopes. Construction Requirements The area to be covered shall be properly prepared. Materials ~ All materials shall meet the requirements of the following specifications. blank . The top side of the blanket shall be covered with a biodegradable extruded plastic mesh. 100 I . The contractor shall maintain the blanket until all work on the contract has been completed and accepted. A common row of staples shall be used on adjoining blankets. on top and the fibers shall be in contact with the soil. the netting shall before the blanket is placed. alternating the center row so that the staples form an "X" pattern. This junction slot shall be stapled across at 8-inch intervals. The end of upstream blanket shall overlap the buried end of the downstream blanket a maximum of 8 inches and a minimum of 4 inches. reseeded.162 or larger in diameter.875 Tb + 10 percent 80 yd3. Maintenance shall consist of the repair of areas where damaged by any cause. "T" shaped pins shall have a minimum length of 8 inches after bending. Adjoining blankets (side by side) shall be offset 8 inches from center of ditch and overlapped a minimum of 4 inches. The blanket shall be made smolder resistant without the use of chemical additives. The blanket shall consist of a machine produced mat of curled wood excelsior of 80 percent. and remulched as directed. The bar of the "T" shall be at least 4 inches long with the single wire end bent downward approximately 3/4-inch.shall be unrolled in the direction of the flow of water. 8 inches or longer fiber length with consistent thickness and the fiber evenly distributed over the entire area of tie blanket. at 4-foot intervals.CURLEDWOODMAT I Description This work consists of necessary to install curled directed by the engineer. fertilized. and see When the mat is unrolled. forming a junction slot. Use 6 staples across the start of each roll. Width Length Weight Weight Volume per per per 48 inch + 1 inch 180 ft average 78 lb + 8 lb 0. In ditches. and all other work incidental to finished construction in accordance with these specifications. and the contractor may be required of the excess without cost to the State. which price shall be full compensation for furnishing all materials. Mat placed outside the specified measured or paid for. Basis in place and accepted. completely will be measured by the square yard of finished surface. made for overlap. tools. No allowance will be limits will not be to remove and dispose of Payment Quantities shall be paid for at the contract unit price per square'yard and shown in the bid schedule. the placing of the matting.Measurement for Payment Curled wood mat. including staples. 101 9 . the preparation of the subgrade. and labor. oats. Areas on which straw is to be applied shall be prepared such that the straw will be incorporated into the soil to the degree specified. The net sha 11 be furnished iI following characteristics: 48 inch. ditch. furnishing with net on materials roadway and performing all ditches or slopes.000 ft*. beforc to be used i! been used fol be an extruded polypropylene or other approve' extruded in such a manner as to form a net 01 square openings. convenient minimum lengths Pins and staples shall be made of high carbon iron wire 0.6 lb/l. Straw shall be derived from wheat. straw may be pneumatically applied by means of equipment which will not render the straw unsuitable for incorporation into the soil. Straw.STRAW WITHNET Description This work consists of necessary to install straw directed by the engineer. "T" shaped pins shall have a minimum length of I inches after bending. Requirements Plastic net shall be placed as soon as possible been completed in locations designated in the to secure straw mulch to the finished slope or after plans. The been obtained by law. minimum 50 yard. Construction have only barley. The bar of the "T" shall be at least 4 inche: long with the single wire end bent downward approximately 3/4-inch. "U" shaped staples shall have legs 8 inches ion! and a l-inch crown. or contractor shall furnish evidence that clearance has from the county agricultural commissioner. Straw shall be uniformly spread at the rate specified in the special provisions. b.162 01 larger in diameter. Straw that has stable bedding shall not be used. ! 102 ~ . When weather conditions are suitable. Removing and disposing of rocks and debris from embankment: constructed as part of the work will be considered as included in the contracl price paid per ton for straw and no additional compensation will be allower therefore. as required straw obtained from outside the county in which it is delivered to the site of the work. Plastic net shall plastic material. minimum. mulching operatioru Net shall be usec Preparation shall include all the work required to make ready the area: for incorporating straw. 2. 3/4-inch minimum rolls to meet the Width Length Weight c. or worl a: Materials a. placed approximately 8 inches apart. insert staples down center of net so that the staples alternate form an "X" shape pattern. the trench shall be backfilled and tamped. After the edge is buried and stapled. made of approximately 7/8-inch steel plate. Insert 1 staple tom of edges of the net. The top edge of the net shall be buried and stapled at the top end of the slope in a narrow trench 6 inches deep. completely in place and accepted. Basis of Payment Quantities shall be paid and shown in the bid schedule nishing all materials. A17 damaged areas shall be repaired to reestablish the condition and grade of the soil prior to application of the covering and shall be refertilized. shall be incorporated into the soil with a roller equipped with straight studs. for at the contract unit which price shall be full and labor. and remulched as directed. and shall be rounded to prevent withdrawing the straw from the soil. The net shall be unrolled from the top to the bottom of the slope. and accordance with these . Maintenance shall consist of the repair of areas where damaged by any cause. an overlap of every foot along top and botover 4 feet on each edge and between edges and center to The contractor shall maintain the straw with net until all work on the contract has been completed and accepted. In piece 4-inch cases where one roll shall be brought over overlap. reseeded. and staggered. all other work incidental to specifications. roll roll starts. so that the upslope there is a side by side. The net shall be applied smoothly but loosely on the mulched surface without stretching. No allowance will be made for overlap. the preparation finished construction in 103 price per square yard compensation for furof the subgrade. The roller shall be of such weight as to incorporate the straw sufficiently into the soil so that the straw will not support combustion and will leave a uniform surface.Straw . Measurement for Payment Straw with net. of net ends and a second the start of the second Where two or more widths of net are applied at least 4 inches must be made. The studs shall not be less than 6 inches long or more than 6 inches wide. and the contractor may be required to remove and dispose of the excess net without cost to the State. will be measured by the square yard of finished surface. Also. tools. including staples. Straw and net placed outside the specified limits will not be measured or paid for. melt-bonded at their intersections. The mat shall comply with the following physici properties: Material type Filament Weight Thickness Nominal Nominal Co1 or diameter width length Nylon 6 plus a minimum canter of 0. forming a stable mi of suitable weight and configuration. Construction x 12 inch gauge or lb/inch.SYNTHETIC MAT Description This work consists necessary to install nylon the engineer. or as directed WOI I Materials Synthetic mat shall consist of three-dimensional structure of entanglt nylon monofilaments.0157 inch. water-permeable.747 + 0. and highly resistant to chemicals al pliable. 0. 50 percent. of furnishing mat on roadway materials ditches and performing all or slopes. The mat shall be crush-resistani resilient. one-piece or two-piece 2 Compression crosshead : Requirements All surfaces to be protected shall be graded and stable and firm. 100 16/in2 104 to obtain on 2 inch finished shall filament x 2 inch so as to be reworked bond sample sizl I .5 percent by weight of carbon black 0. Prepared surfaces that become crusted an acceptable condition before placing the mat. lb/inch. minimum 0.l inch x 2 inch inch x 12 inch x 6 inch. 50 percent.162-inch ungalvanized steel "T" pins. minimum 38 inch 109 yard Black of roll of roll Tensile properties' Strength Length direction Width direction Elongation Length direction Width direction Resiliency2 30 minute (3 cycles) 7.70 i%h.075 lb/yd2 0. ASTM D 1682 strength to minimum minimum Strip test procedure modified indicate tensile properties.4 recovery Pins shall be . environmental degradation. minimum wedge-shaped wood stakes or larger. minimum minimum 80 percent.5 4. load cycling of speed of 2 in/min. the allowing mat 'has been placed. All All steel wood stakes pins shall shall be driven be driven flush to within 2 inches of to the ground surface. complete. the area shall be evenly to the grade through the the blanket Maintenance until shall seeded openings as spein the all work on the contract consist of the repair of Payment Synthetic mat. which price shall be full compensation for furnishing all materials. and all other work incidental to finished construction in accordance with these specifications. Start the installation tial strip placed in the center of the ditch to avoid an overlap of the ditch. the seeds to drop The contractor has been completed areas where damaged Measurement for shall maintain and accepted.Synthetic mat used as a ditch lining shall be applied with roll laid parallel to the flow of water. will be measured by the square yard of finished surface. with the upslope width lap joints and upslope edges shall be pinned or staked at intervals or less. All of 3 feet ground surface. tools. and accepted.f mat used as ditch lining shall terminate on 6-inch wide horizontal shelves running parallel to the axis of the ditch for the full length of the ditch. Edges of the mat shall be pinned or staked at 3-foot intervals. At least 12 inches of the end of the mat shall be buried vertically in a slot dug in the soil. 105 . Upslope edges o. including pins or stakes. mat. Check slots shall be spaced so that a check slot occurs within each 25 feet. Basis of Payment Quantities shall be paid for at the contract unit price per square yard and shown in the bid schedule. in place. Pin or stake the overlap by placing 3 pins or stakes evenly spaced across the end of each of the overlapping lengths and by placing 3 pins or stakes across the width of the center of overlap area. Pin or stake the mat in the check slot at each edge overlap and in the center of mat. The soil shall be firmly tamped against the mat in the slot. the preparation of the subgrade. by any cause. and labor. Successive lengths of mat shall be overlapped at least 3 feet. placing of the mats. with the upstream length on top. a longitudinal of not less than 3 inches shall be used. Check slots shall be constructed by placing a tight fold at least 8 inches vertically into the soil. The mat shall be secured in the anchor slot by pins or stakes at intervals of 3 feet or less prior to burying. and tamped to original slope. Where more than one width is required. After cified. the the length of with the iniin the center lap joint on top. Mat placed outside the specified limits will not be measured or paid for and the contractor may be required to remove and dispose of the excess mat without cost to the State. An anchor slot shall be placed at the upslope and downslope ends of the mat placement. backfilled with soil. crushed rock. The gradation of material in each layer of the filter blanket shall meet the requirements of the special provisions.to the riprap surface. of the thickness shown on the plans. shall be measured by the number of cubic yards as computed from surface measurement parallel to the riprap surface and thickness measured normal . reasonably free from thin. the preparation of the subgrade. 106 . using methods which will not cause segregation of particle sizes within the filter material. and labor. of specified thickness and extent. Construction Requirements A filter blanket shall be placed on the prepared slope or area to the full specified thickness of each layer in one operation. areas where damaged by any cause. and elongated pieces. Multiple layers of filter material. shall be placed in the same manner. or sand. and all other work incidental to finished construction in accordance with these specifications. furnishing materials blanket on roadway and performing all work ditches or slopes. tools. using methods which will not cause mixture of the material in the different layers. when shown on the plans. The contractor shall maintain has been completed and accepted. flat. All material comprising the filter blanket shall be composed of tough. Blanket placed outside the specified limits will not be measured or paid for. and the contractor may be required to remove and dispose of the excess without cost to the State. and shall be free from organic matter. which price shall be full compensation for furnishing all materials.FILTER BLANKET Description This work consists of necessary to install filter directed by the engineer. durable particles. The surface of the finished layer should be reasonably even and free from mounds or windows. Basis of Payment Quantities shall be paid for at the contract unit price per cubic yard. The filter blanket shall be placed in accordance with various sections these specifications requiring the use of a filter blanket or as specified the engineer. or as Materials The filter blanket will consist of one or more layers of gravel. placing of the filter blanket. in place and accepted. the blanket Maintenance until shall of by all work on the contract consist of the repair of Measurement for Payment j The quantity of filter blanket to be paid for. the fabric Maintenance until shall all work on the contract consist of the repair of Measurement for Payment Engineering fabric to be paid for. For Edge Drains For Underdrains 40 4. materials and performing all work on roadway ditches or slopes. Weight. wicking agent. requiring the use of engineering fabric. or Materials The filter pylene material. in place and accepted. D 1682 Toughness. or polyproThe material shall not act as a or a combination thereof.000 4. nylon. 1 In each direction 107 i . will be measured in square yards in accordance with the provisions in the various sections of these specifications.000 Requirements Engineering fabric shall be placed to the specified thickness in accordance with various sections of these SpecificatSons requiring the use of an engineering fabric or as specified by the engineer. of specified thickness and extent. areas where damaged by any cause. Elongation.ENGINEERINGFABRIC Description This work consists of furnishing necessary to install engineering fabric as directed by the engineer. ounces/yd2. minimum ASTM Designation D 1910 Grab tensile minimum1 strength (l-inch grip). minimum (percent elongation x grab tensile strength) Construction 50 90 10 30 3.0 lb. percent. minimum ASTM Designation. and shall conform to the following crishall be permeable. teria: fabric shall be manufactured of polyester. The contractor shall maintain has been completed and accepted. Basis of Payment Quantities shall be paid for in accordance with the provisions in the various sections of these specifications requiring the use of engineering fabric. lb. FREEBOARD. the capacity to adjust material that allows for top galvanized time when any causes motion. below riprap pore spaces among the particles running heavy equipment over Permeable and permit One or more to prevent textile natural bed of a channel location purposes. DEPTH OF FLOW. face. LINING. typically exfiltration. piping BLANKET. of lining materials channel and vegetated designed of by water n. Compartmented rectangular containers onal wire mesh and filled with stone. riprap LINING. Vertical distance at design condition. Lining constructed PERMANENT. The closing generally caused construction. Conditions factors responsible for LINING. the soil during to fabric) occur. COMPACTION. channel. return period ENGINEERING prevent FILTER of by distance from the Discharge at a specific to be used for design FABRIC. COMPOSITE.. FLEXIBLE. -RADIUS. Lining made by wetted the water sur- by an appropriate used below riprap to exerted at or at rest.. Vertical DESIGN DISCHARGE. Angle critical equilibrium of slope formed by particulate material condition of incipient sliding. surface GABION. flow at constant divided Resistance described Pressure velocity INCIPIENT MOTION. a depth the below as it the 108 long of the steel channel hexag- term moves through a water surface for increase in a given cross upper banks). (e. encountered by Manning's at that particle Combination in low-flow of soil and rock. as measured by the size of a glass percent or less by weight will pass through the fabric the equivalent opening size. Measure of the largest effective engineering fabric. point in movement material with of a porous to perimeter. under APPARENT OPENING SIZE (AOS). EOS). in section to settlement infiltration and . HYDRAULIC the use. opening in an bead where five (formerly called layers of graded noncohesive material placed soil piping and permit natural drainage. defined (or filter seepage to from the water Flow area HYDRAULIC RESISTANCE.GLOSSARY ANGLE OF REPOSE. commonly HYDROSTATIC PRESSURE.g. Force developed due to the shear stress acting on the perimeter of a channel section which acts in the direction of flow on the channel bed. horizontal horizontal Value of hydraulic PERMISSIBLE. Equals the shear stress on the channel section multiplied by the wetted channel area. RETARDANCE CLASSIFICATION. at which Local increases in water move through resistance slopes to or of the in flow chan- with to a interstices stone. SIDE SLOPE. baskets on the force air of RIPRAP. enables cobbles. the or th. TRACTIVE FORCE. Consists of wire together. Force wetted area of per unit wetted shear stress conditions.at occurring in a channel channel lining will the Slope of the sides of a channel. designed for short term of a permanent vegetative a uniform channel of that a soil utilization.ly l-l/2:1.r LINING. RIGID. 109 a .. nels for protection a roadmain acts in section fail. or boulders against the action stone or prepared RIPRAP. CHANNEL. used to deliver collect it SHEAR STRESS. Stabilized drainageway and adjacent areas and to way drainageway.O. Depth PERMEABILITY. typically flow. Force developed the direction of the flow. TEMPORARY. Lining material constructed of nonporous large conveyance capacity LINING. RIPRAP. lining. it. Qualitative description offered by various types of vegetation.5 to 1 . to adjust to settlement smooth finish that provides soil cement). for a given set of to the placed on side of water. of or RIPRAP. DUMPED. Property of with no capacity material with (e. meaning vertical. Consists filled with portland of riprap with cement mortar. GROUTED. distance first as 1. to broken concrete dumped in place to form a well-graded mass with filled SHEAR STRESS. water or graded slope all or part ROADWAY CHANNEL.'channel area.5 feet to l-foot SUPERELEVATION. and anchored to the slope. SHEAR STRESS. Broken rock. Consists on a filter blanket minimum of voids. distance of 1. surface on the outside of a bend. It is customary to name the or frequent. concrete. assist in Lining development NORMAL DEPTH. water an connected from inlet the.g. WIRE-ENCLOSED. Sf = So where Sf is t friction slope and So is the bed slope). VELOCITY.loss due to frictio is equal to bed slope of the channel (i. MEAN. PERMISSIBLE.r UNIFORM FLOW. the channel. divided Mean velocity by the area of the water cross section. Discharge VELOCITY..e. The flow condition where the rate of head. that 110 will not cause serious erosion of . (6) N. Olsen and Q.' Reviewed by D. 1969. 120. Report Book No. 1987.S.J.E. ASCE. (9) U. R. 1951.L.B.M. in Cooperation with U. Chow. and J.S.S. 105. Stable Hyd. Paper 14898. Laboratory Report N. 1955. Painta. Hydraulic Engineering Circular (4) Soil Conservation Service. 3. "Velocity Measurements in a Channel Lined with Flexible Plastic Roughness Elements.REFERENCES (1) Federal Highway Administration. 1233-1245." Technical Report No. Highway Research Board. pp.D. Colorado State University. Oklahoma. Open Company. CER79-80-RML-DBS-11. 329-342. Part II. Hydraulics Branch. Department of Civil Engineering.A. D. Roadside Channels." Louisiana Department of Highways. "Erosion Control Study.M. Hill. 11." and Water McGraw-Hill Lab. Glover. Stillwater. Lawson. Flow Retardance in Vegetated Channel. HYlO. September 27. "Handbook of Channel Design for Soil Conservation. Florey. (11) M. SP-34. Fort Collins." NCHRP Report No.T.C." Transactions ASCE. Analytical and Finite-Difference Methods." SCS-TP-61. Federal Highway Administration.B.C. "Design of Stable Channels. Kouwen. Davenport. (10) O.T. J. pp. October. Colorado." Hydraulic Design Series No. Vol.A. and H. "Use of Riprap No. Proc. (8) A. Cox. and D. 1980. 1971. Bureau of Public Roads. Department of Transportation. 111 . Anderson." Journal of the Hydraulics Division. (13) R. 1952. McHenry and R. R. 108. Bureau of Reclamation. "Tentative Design Procedure for Riprap Lined Channels.. 1970. (5) N. Unny. Irrigation and Drainage Division. (12) E. Townsend. Simons. "Design of Roadside Drainage Channels. No. Li. 14." Hydraulics Branch. "Shear Stress Distribution in Stable Channel Bends. "Sedimentation Studies in Open Channels: Boundary Shear and Velocity Distribution by Membrane Analogy. T. 1954.E. Kouwen. August 5. Lane. (3) Federal Highway Administration. for Culverts and Channels. Bank Protection. 325.G. 1959). Channel Profiles. U. Channel "Hydraulic Hydraulic Design of Energy Dissipators Engineering Circular No. Hydraulics (New for York. 1965. Nouh and R. (7) V. 1983. IRZ. National Academy of Sciences. Vol. A. Washington.L. Adams. Bureau of Reclamation. 19/9. (2) Federal Highway Administration. and T. S. Course Sediment Publications. 4 Applied 'o Experiment Columbia~. I and Riprap Design. Mississippi. (16) E. (15) "Performance K. 1982. HY12. Administration.B. Resources (22) S. Galloway. No. "Resistance Equation Large-Scale Roughness. Geological Survey. PP. Proc. Stat 1 University. Engineering Manual. ASCE. Motion 111.E." Conducted for Mississippi State Highway Department in Cooperation with U. Clark.1 (14) J. Federal Highway Administration. 1968. Analysis Volume VI. by the Agricultural and Biological Engineerin Mississippi Department. R." Federal Highway of Temporary Ditch Linings. Report No. I (20) J. and R. December 1979. McConaughy.“’ No.S. T.N.B.G. FHWA-RD-30. I Collinsl. Beaseley. 3. Hydroplaning. D ecember 1981. "The Tractive Stability of Open Channels in Cohesive Soils. "Incipient Journal of Hydraulics Division. University Station. 107. and D." Journal of the Hydraulics Division.M. 715. "Evaluation of Design 'Practices for Rock Riprap Protection of Channels near Highway Structures. "Pavement and Geometric Design Criteria for Minimizing Texas Transportation Institute." Iterim ReportIs Highway Administration by U.. March 19851. and Design American Text. Prepared for Federal Survey. of Open Association 112 FHWA. pp. State College." Research Bulletin No.M. Force Theory Agricultural of Missouri. 1 to 17. 1985. (21) D. Gulf Coast Hydroscience 1982 to 1985.T. Wang and H.P.C.W. Senturk. Sacramento. Prepared in Cooperation with the Federal Highway Administration Preliminary Draft. California. Carpenter.G." of State Highway Drainage Highway Officials. (17) B. Simons and Colorado: Water F.C. Department of Transportation. 1593-1613. Agricultural Experiment Station. Smerdon and R. Vol. ~ Transport 19//j. Bathurst. Channels. McWhorter. Paper 14239 . (23) "Hydraulic Guidelines. . Sediment ASCE. Missouri. 1985. October 1959. Blodgett and C. Simons." U. Technology (Fort for Voll.C. Shen. Texas A&M University. Li. "Erosion Contro Criteria for Drainage Channels. Thibodeaux. (18) "Geotextile (19) J.Y. Geologica~l Center and Computer Science CorporationI. 52-538.S. Design Guide DG-2 FHWA HEC-14. Chapter XI Riprap Basins 6 DG2 .1 6/05 . This page left intentionally blank. 6 6/05 DG2 .2 . . . . . Engineering Field Handbook Chapter 16 Streambank and Shoreline Protection 6 DG3 .Design Guide DG-3 NRCS.1 12/03 . 6 12/03 DG3 .This page left intentionally blank.2 . United States Department of Agriculture Natural Resources Conservation Service Chapter 16 Engineering Field Handbook Streambank and Shoreline Protection . religion. DC 20250. To file a complaint. Cumberland Gap National Park. Sotir & Associates) The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race. political beliefs. sex.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Issued December 1996 Cover: Little Yellow Creek.) should contact the USDA Office of Communications at (202) 720-2791. 16–ii (210-vi-EFH. age. Kentucky (photograph by Robbin B. USDA is an equal employment opportunity employer. Department of Agriculture.) Persons with disabilities who require alternative means for communication of program information (braille. write the Secretary of Agriculture.S. large print. Washington. color. (Not all prohibited bases apply to all programs. or call 1-800-245-6340 (voice) or (202) 720-1127 (TDD). and marital or familial status. December 1996) . audiotape. national origin. disability. U. etc. Chapter 16 Preface Chapter 16. is one of 18 chapters of the U. Chapter 16 are: Chapter 1: Chapter 2: Chapter 3: Chapter 4: Chapter 5: Chapter 6: Chapter 7: Chapter 8: Chapter 9: Chapter 10: Chapter 11: Chapter 12: Chapter 13: Chapter 14: Chapter 15: Chapter 17: Chapter 18: Engineering Surveys Estimating Runoff Hydraulics Elementary Soils Engineering Preparation of Engineering Plans Structures Grassed Waterways and Outlets Terraces Diversions Gully Treatment Ponds and Reservoirs Springs and Wells Wetland Restoration.S. Department of Agriculture. Some techniques presented in this text are rapidly evolving and improving. therefore. Streambank and Shoreline Protection. Enhancement. or Creation Drainage Irrigation Construction and Construction Materials Soil Bioengineering for Upland Slope Protection and Erosion Reduction This is the second edition of chapter 16. December 1996) 16–i . Other chapters that are pertinent to. and should be referenced in use with. additions to and modifications of chapter 16 will be made as necessary. Natural Resources Conservation Service. (210-vi-EFH. previously referred to as the Engineering Field Manual. Engineering Field Handbook. Mary R. Saele. New Jersey. NRCS. illustrator. Fort Worth. drainage engineer (retired). and photographs. served a coordination role in the review and revision of the chapter. and Frank F. United States Department of Agriculture. Mattinson. provided editing assistance and desktop publishing in preparation for printing. Wenberg. NRCS. NRCS. Oregon. Somerset. director. national drainage engineer (retired). Fort Worth. visual information specialist. plant materials specialist (retired). 16–ii (210-vi-EFH. editor. Georgia. dormant post plantings. Portland. national landscape architect. Wayne Everett. sedimentation geologist (retired). H. December 1996) . and Wendy R. Marietta. Leland M. Adams. design engineer. Texas. Reckendorf. John D. which were adapted for NRCS use. NRCS. In addition to authoring sections of the revised manuscript. Sotir & Associates. Escheman. Texas. and stream barbs. Formanek. NRCS. Massey. supplied the plant species information in the appendix. rootwad/boulder revetments. In addition these authors revised the manuscript to reflect new research on stream classification and design considerations for riprap. Gary E. Robbin B. Fort Worth. Texas. agricultural engineer. edited the manuscript to extend its applicability to most geographic regions. and Richard D. was a major contributor to the inclusion of soil bioengineering and revision of the chapter. Walter K. Seattle. and Robert T. Watershed Science Institute. Washington. NRCS. they supplied original drawings. Twitty.Chapter 18 Acknowledgments This chapter was prepared under the guidance of Ronald W. Tuttle. Pierce. Carolyn A. landscape architect. Natural Resource Conservation Service (NRCS). ........................................... 16–3 (b) Planning and selecting stream-bank protection measures ..........Chapter 16 Contents: 650....................................................................1602 Categories of protection ................................................................................ 16–63 (c) Protective measures for shorelines ... December 1996) 16–9 16–iii ............................................................................. 16–10 Shoreline protection 16–63 (a) General .................................1603 References 16–81 Appendix A Size Determination for Rock Riprap 16A–1 Appendix B Plants for Soil Bioengineering and Associated Systems 16B–1 Tables Table 16–1 Live fascine spacing 16–16 Table 16–2 Methods for rock riprap protection 16–49 Figure 16–1 Appropriate selection and application of streambank Figures 16–2 or shoreline protection measures should vary in response to specific objectives and site conditions Figure 16–2 Vegetative system along streambank (210-vi-EFH...................... 16–3 (c) (d) 650.............................1601 Streambank protection 16–3 (a) General ........................................... 16–6 Protective measures for streambanks .................................. 16–1 (b) (c) 650... 16–1 Selecting streambank and shoreline protection measures .................. 16–64 650.............1600 Streambank and Shoreline Protection Introduction 16–1 (a) Purpose and scope ....................................................... 16–63 (b) Design considerations for shoreline protection ............................ 16–1 Design considerations for streambank protection . Chapter 16 Streambank and Shoreline Protection Part 651 National Engineering Handbook Figure 16–3a Eroding bank. Vermont. 1941 Figure 16–3d Soil bioengineering system. Winooski River. Vermont. Winooski River. Winooski River. June 1938 16–12 Figure 16–3b Bank shaping prior to installing soil bioengineering 16–12 practices. Vermont. 16–12 June 1993 (55 years after installation) Figure 16–4 Live stake details 16–13 Figure 16–5 Prepared live stake 16–15 Figure 16–6 Growing live stake 16–15 Figure 16–7 Live fascine details 16–17 Figure 16–8 Preparation of a dead stout stake 16–18 Figure 16–9a Placing live fascines 16–18 Figure 16–9b Installing live stakes in live fascine system 16–18 Figure 16–9c An established 2-year-old live fascine system 16–18 Figure 16–10 Branchpacking details 16–20 Figure 16–11a Live branches installed in criss-cross configuration 16–21 Figure 16–11b Each layer of branches is followed by a layer 16–21 of compacted soil Figure 16–11c A growing branchpacking system Figure 16–12 16–23 Figure 16–13a A vegetated geogrid during installation 16–24 Figure 16–13b A vegetated geogrid immediately after installation 16–24 Figure 16–13c Vegetated geogrid 2 years after installation 16–24 Figure 16–14 iv Vegetated geogrid details 16–21 Live cribwall details 16–26 Figure 16–15a Pre-construction streambank conditions 16–27 Figure 16–15b A live cribwall during installation 16–27 (210-vi-EFH. September 1938 Figure 16–3c Three years after installation of soil bioengineering 16–12 practices. December 1996) . and boulder revetment details 16–36 Figure 16–23 Rootwad. and willow transplant 16–37 revetment system.Chapter 16 Streambank and Shoreline Protection Part 651 National Engineering Handbook Figure 16–15c An established live cribwall system Figure 16–16 Joint planting details 16–27 16–28 Figure 16–17a Live stake tamped into rock joints 16–29 Figure 16–17b An installed joint planting system 16–29 Figure 16–17c An established joint planting system 16–29 Figure 16–18 Brushmattress details 16–31 Figure 16–19a Brushmattress during installation 16–32 Figure 16–19b An installed brushmattress system 16–32 Figure 16–19c Brushmattress system 6 months after installation 16–32 Figure 16–19d Brushmattress system 2 years after installation 16–32 Figure 16–20 Tree revetment details 16–34 Figure 16–21a Tree revetment system with dormant posts 16–35 Figure 16–21b Tree revetment system with dormant posts. Weminuche River. 16–35 2 years after installation Figure 16–22 Log. rootwad. boulder. CO Figure 16-24 Dormant post details 16–38 Figure 16–25a Pre-construction streambank conditions 16–39 Figure 16–25b Installing dormant posts 16–39 Figure 16–25c Established dormant post system 16–39 Figure 16–26 Piling revetment details 16–41 Figure 16–27 Slotted board fence details (double fence option) 16–42 Figure 16–28 Slotted board fence system 16–43 Figure 16–29 Concrete jack details 16–44 Figure 16–30 Wooden jack field 16–45 (210-vi-EFH. December 1996) v . with 16–56 deposition in foreground vi Figure 16–40 Stream barb details 16–58 Figure 16–41 Stream barb system 16–59 Figure 16–42 Vegetated rock gabion details 16–61 Figure 16–43 Vegetated rock gabion system 16–62 Figure 16–44 Timber groin details 16–65 Figure 16–45 Timber groin system 16–66 Figure 16–46 Timber bulkhead system 16–67 Figure 16–47 Timber bulkhead details 16–68 Figure 16–48 Concrete bulkhead details 16–69 Figure 16–49 Concrete bulkhead system 16–70 Figure 16–50 Concrete revetment (poured in place) 16–71 Figure 16–51 Rock riprap revetment 16–71 (210-vi-EFH. December 1996) .Chapter 16 Streambank and Shoreline Protection Part 651 National Engineering Handbook Figure 16–31 Concrete jack system several years after installation 16–46 Figure 16–32 Rock riprap details 16–47 Figure 16–33 Rock riprap revetment system 16–48 Figure 16–34 Concrete cellular block details 16–50 Figure 16–35a Concrete cellular block system before backfilling 16–51 Figure 16–35b Concrete cellular block system several years 16–51 after installation Figure 16–36 Coconut fiber roll details 16–52 Figure 16–37a Coconut fiber roll 16–53 Figure 16–37b Coconut fiber roll system 16–53 Figure 16–38 Stream jetty details 16–55 Figure 16–39a Stream jetty placed to protect railroad bridge 16–56 Figure 16–39b Long-established vegetated stream jetty. December 1996) vii .Chapter 16 Streambank and Shoreline Protection Part 651 National Engineering Handbook Figure 16–52 Live siltation construction details 16–74 Figure 16–53 Live siltation construction system 16–75 Figure 16–54 Reed clump details 16–77 Figure 16–55a Installing dead stout stakes in reed clump system 16–78 Figure 16–55b Completing installation of reed clump system 16–78 Figure 16–55c Established reed clump system 16–78 Figure 16–56 Coconut fiber roll details 16–79 Figure 16–57 Coconut fiber roll system 16–80 (210-vi-EFH. .This page left intentionally blank. They range from vegetationoriented remedies. Structures may still be viable options. protect from erosion in both ways. Projects planned and installed in this context are more likely to be successful. living materials for restoration. and designs that reduce flow velocity fall into the first category of protection. many organizations involved in water resource management have given preference to engineered structures. and • retain or enhance the stream corridor or shoreline system. These systems can be used alone or in combination. In the recent past.g. estuaries. and log. As a first priority consider those measures that • are self sustaining or reduce requirements for future human support. Examples include permeable fence design. (210-vi-EFH. it is also acknowledged that this should be done on a selective basis. The second category includes channels lined with grass. biological. (c) Selecting streambank and shoreline protection measures This document recognizes the need for intervention into stream corridors to affect rehabilitation. grade reduction. jacks. gabions. to engineered grade stabilization structures (fig. however. groins. preference should be given to those methods that restore the ecological functions and values of stream or shoreline systems. such as soil bioengineering. Rehabilitation of highly degraded systems is also important. either alone or in combination with structures. barbs. and boulder combinations. it is most effective to select areas within relatively healthy systems. After deciding rehabilitation is needed. soil bioengineering. and structural systems. so using revetments for spot protection may move erosion problems downstream or across the stream channel. • improve water quality through reduction of temperature and chronic sedimentation problems. lakes.. e. concrete. (b) Categories of protection The two basic categories of protection measures are those that work by reducing the force of water against a streambank or shoreline and those that increase their resistance to erosive forces. Most designs that employ brushy vegetation. drop structures. The information in chapter 16 does not apply to erosion problems on ocean fronts. riprap. in a growing effort to restore sustainability and ensure diversity. stream jetties. tree or brush revetments.Chapter 16 Streambank and Shoreline Protection 650. Revetment designs do not reduce the energy of the flow significantly. however. but these systems often require substantial investment of resources and may be so modified that partial success is often a realistic goal. cellular concrete. These measures can be combined into a system. and excavated channels against scour and erosion by using vegetative plantings. or other areas of similar scale and complexity. • use native. and chemical functions and values of streams or shorelines. 16–1). These measures can be used alone or in combination. When selecting a site or stream reach for treatment. • provide opportunities to connect fragmented riparian areas. and other revetment designs. increasing channel sinuosity.1600 Introduction (a) Purpose and scope Streambank and shoreline protection consists of restoring and protecting banks of streams. and it is often critically important to prevent the decline of these healthier systems while an opportunity remains to preserve their biological diversity. a variety of remedies are available to minimize the susceptibility of streambanks or shorelines to disturbance-caused erosive processes. • restore the physical. soil bioengineering. rootwad. large river and lake systems. December 1996) 16–1 . Stormwater reduction or retention methods. ." se h .. rit teg n i V=average velocity r = hydraulic radius Chapter 16 Streambank and Shoreline Protection n it he w tends (210-vi-EFH. December 1996) ot Part 650 Engineering Field Handbook .. ..49r2/3s1/2/n where "A co m m .. It i s wr on g er w i Less coefficient Figure 16–1 Appropriate selection and application of streambank or shoreline protection measures should vary in response to specific objectives and site conditions (Aldo Leopold) s=channel slope n= roughn 16–2 ds s y..t en pr e s er ve th e ab li t y and bea uty o f the bio tic .. i to a=cross sectional flow area thing is right when it t V=1. un it y. debris jams. It should anticipate the changes most likely to occur or that are planned for the near future: • Climatic regime. When selecting protective measures. hydrologic conditions. vegetative. wetted perimeter). or constrictions. Streambank erosion is a natural process that occurs when the forces exerted by flowing water exceed the resisting forces of bank materials and vegetation. such as channel confinement or realignment and damage to or removal of vegetation. • • Stream reach characteristics Soil and streambank materials at site. boulders. wavelength. amount. analyze the needs of the entire watershed. climatic. the riparian corridor. Bed material d50 based on a pebble count. are major factors in streambank erosion.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook • Projected development over anticipated project life. prior stream modifications. Reducing runoff and soil loss from the upland portions of the watershed using sound land treatment and management measures normally makes the streambank protection solution less expensive and more durable. but normally work in an interrelated manner. belt width. determine what triggered the problem.1601 Streambank protection (a) General The principal causes of streambank erosion may be classed as geologic. water quality. and hydraulic. Quality. However. In many cases streambed stabilization is a necessary prerequisite to the placement of streambank protection measures. Channel alignment. Suspended load and bedload as needed. consider the stream as a system that is affected by watershed conditions and what happens in other stream reaches. meander wavelength. meander amplitude. and types of terrestrial and aquatic habitat. width. determine the cause of erosion at each site. • Sediment load (suspended and bedload). bank irregularities. Identification of specific problems arising from flow deflection caused by sediment buildup. and previous treatments. and shape (width/depth. land use changes or natural disturbances can cause the frequency and magnitude of water forces to increase. Channel realignment often increases stream power and may cause streambeds and banks to erode. terrestrial habitat. (3) Hydrologic/hydraulic data • Flood frequency data (if not available. includes data commonly needed for planning purposes. 650. • Channel slope. Loss of streamside vegetation can reduce resisting forces. estimate using regional equations or other procedures). past stability problems. the effects that stream protection may have on other reaches. and aesthetics. and natural disturbances that might influence stream behavior. December 1996) 16–3 . • If bank erosion problems are localized. (210-vi-EFH. These causes may act independently. • Estimates of stream-forming flow at 1. (4) • • • • • • The list that follows. • Land use/land cover. and sinuosity to determine stream classification. An analysis of stream and watershed conditions should include historical information on land use changes. Potential streambank failures. depth. • History of land use. • Estimates of width and depth at stream-forming flow conditions. surrounding wetlands. to determine if incoming sediment load can be transported through the restored reach. • Water quality. Present stream width. thus streambanks become more susceptible to erosion.to 2-year recurrence interval and flow velocities. although not exhaustive. Erosion occurs in many natural streams that have vegetated banks. Vegetative condition of banks. depth. aquatic habitat. • • (1) Watershed data When analyzing the source of erosion problems. (b) Planning and selecting streambank protection measures (2) Causes and extent of erosion problems • If bank failure problems are the result of widespread bed degradation or headcutting. Direct human activities. 16–4 Part 650 Engineering Field Handbook (6) Soils A particular soil's resistance to erosion depends on its cohesiveness and particle size. and approaching a stage of dynamic equilibrium). such as urbanization. Such a model is useful in stream restoration work because streams can be observed in the field and their dominant process determined in the reach under consideration (i. width-to-depth ratio. and stream sinuosity. Sandy soils have low cohesion. However. such as loss of streamside vegetation from human or animal trampling. erosion caused by ice is an additional problem. The first level of classification distinguishes between single or multiple thread channels.e. Several stream subtypes are based on other criteria. C. stream size. William Davis (1899) first divided streams into three stages as youthful. D. Although all these systems served their intended purposes. climatic. Fines are selectively removed from soils that are heterogeneous mixtures of sand and gravel. Tension cracks can also contribute to piping and related failures. (7) Hydrologic. In cold climates where streams normally freeze or partly freeze during winter. they were not particularly helpful in establishing useful criteria for streambank protection and design. These cracks may lead to slab failures on oversteepened banks. and vegetative conditions Stream erosion is largely a function of the magnitude and frequency of flow events. resulting in sloughing of the streambank and its overlying material. tension cracks may develop parallel to and several feet below the top of the bank. This geometry is then extrapolated to unstable stream reaches to derive a template for potential channel design and reconstruction.. Watershed changes that increase magnitude and frequency of flooding. Because unvegetated banks made up of expansive clays are subject to shrinkage during dry weather. 1963 and 1977). often compound the streambank erosion effect. E. B. and increased surface runoff. The resistance of cohesive soils depends on the physical and chemical properties of the soil as well as the chemical properties of the eroding fluid. the hydraulic removal of fines and sand from a gravel matrix may cause it to collapse. Predicting a stream's behavior based on appearance is also a feature of the Schumm. December 1996) . deforestation. Lenses or layers of erodible material are frequent sources of erosion. and meander pattern. mature and old age. and Watson (1984) channel evolution model developed for Oaklimeter Creek in Mississippi. F. Associated changes. contribute to streambank erosion. and G). Streams were later classified by their pattern as straight. bentonite. depositional features. flow regimes. Rosgen's (1992) stream classification system goes beyond the channel evolution model as it is based on determining hydraulic geometry of stable stream reaches. The streams are then separated based on degrees of entrenchment. through aggradation and stabilization of alternate bars. or other expansive clays. based on a hierarchical system. such as average riparian vegetation. organic debris and channel blockages. DA. Flow duration is of secondary importance except for flows that exceed stream-forming flow stage for extended periods. meandering. Harvey. This system has been updated several times (Rosgen. The present version of Rosgen's stream classification has several types (A. Cohesive soils often contain montmorillonite. and their particles are small enough to be entrained by velocity flows of 2 or 3 feet per second. Rosgen (1985) developed a stream classification system that categorizes essentially all types of stream channels on the basis of measured morphological features.Chapter 16 Streambank and Shoreline Protection (5) Stream classification Stream classification has evolved significantly over the past 100 years. A streambank's position (outside curve or inside) can also be a major factor in determining its erosion potential. This model discusses channel conditions extending from total disequilibrium to a new state of dynamic equilibrium. 1992) and has broad applicability for communication among users and to predict a stream's behavior based on its appearance. 1957) or by stability and mode of sediment transport (Schumm. active headcutting and transport of sediment. Streambanks are affected by ice scour in several ways: • Streambanks and associated vegetation can be forcibly damaged during freezing or thawing action. or braided (Leopold & Wolman. (210-vi-EFH. leaving behind a layer of gravel that may protect or armor the streambed against further erosion. especially in places where bank support has been reduced by toe erosion. They are further subdivided by slope range and channel materials. increased bank erosion. Several feet of degradation commonly occurs in the reach below the dam before an armor layer develops or hydraulic parameters are sufficiently altered to a stable grade. and increased bar deposition or formation. They move upstream.Chapter 16 Streambank and Shoreline Protection • Floating ice can cause gouging of streambanks. thus decreasing channel capacity. Channelization projects that straighten or enlarge channels often increase one or more of these factors enough to cause widespread erosion and associated problems. conservation treatments that significantly reduce sediment loads can trigger stream erosion problems unless runoff is also reduced. causing bed erosion and bank failure on the main stream and its tributaries. and structural features may be required to modify these cross currents. • trapping sediment. Headcuts often develop in the modified reach or at the transition from the modified reach to the unaltered reach. summer rearing. and • increasing width-to-depth ratio with subsequent lateral migration. flow depth. Streamflows that transport sustained heavy loads of sediment are less erosive than clear flows. and other rock/boulder structures that protect the channel without creating backwater should be considered instead of small rock and log dams. each stage of the life cycle of aquatic species requires different habitats. • Acceleration of flow around and under ice rafts can cause damage to streambanks. channel constrictions. and bank irregularities cause local increases in the energy slope and create secondary currents that produce accelerations in velocity sufficient to cause localized streambank erosion problems. woody vegetation helps to control erosion by adding strength to streambank materials. These localized problems often are treated best by eliminating the source of the problem and providing remedial bank protection. However. • raising flood levels and causing out-of-bank flows to erode new channels. thus preventing ice from forming and encouraging faster thawing. secondary cross currents are also a natural feature around the outside curves of meanders. In watersheds that have high sediment yields. Vortex rock weirs. • Woody vegetation has deeply embedded roots that reinforce soils. reducing flow velocities in the vicinity of the bank. These diverse habitats are needed to meet the unique demands imposed by spawning and incubation. Local obstructions to flow. especially if soils are easily erodible. inducing bank erosion and flood plain scour. and slope. Commonly. (9) Habitat characteristics The least-understood aspect of designing and analyzing streambank protection measures is often the impact of the protective measures on instream and riparian habitats. and retarding tension crack development. (210-vi-EFH. This can easily be seen where dams are constructed on large sediment-laden streams. Installing grade control structures that completely cross a stream and act as a very low head dam may initiate other channel instabilities by: • inducing bank erosion around the ends of the structure. Returning the stream to its former meander geometry is generally the most reliable way to stop headcuts or prevent their development. each having specific characteristics. Once a dam is operational. so the water leaving the structure is clear. • Vegetation helps protect the bank from ice damage. maintain the sediment transport capacity of the channel. The productivity of most aquatic systems is directly related to the diversity and complexity of available habitats. the sediment drops out into the reservoir pool. Part 650 Engineering Field Handbook Grade control structures should be designed to maintain low channel width-to-depth ratios. and overwintering. Erosion from ice may be minimized or reduced by vegetation for the following reasons: • Streambank vegetation reduces damaging cycles of freeze-thaw by maintaining the temperature of bank materials. December 1996) 16–5 . • Vegetation tends to be flexible and absorbs much of the momentum of drifting ice. and provide for passing a wide range of flow velocities without creating backwater and causing sediment deposition. (8) Hydraulic data Stream power is a function of velocity. "W" rock weirs. • Deeply rooted. increasing flow resistance. channel constrictor. • Avoiding or altering construction procedures during critical times. • Scheduling construction activities to avoid expected peak flood season(s). wildlife habitat. design. are also integral factors. boulder placement. the least disturbance to the existing stream system during construction and maintenance produces the greatest environmental benefits. but a more expensive alternative might best meet planned objectives when maintenance. They divide structures into those for rearing habitat enhancement and those for spawning habitat enhancement. 16–6 Part 650 Engineering Field Handbook (11) Social and economic factors Initial installation cost and long-term maintenance are factors to be considered when planning streambank and shoreline protection. • Adopting maintenance plans that maximize riparian vegetation and allow wide. Some protection measures seem to have apparent advantages. Artificial measures typically include rock. Work by Rosgen and Fittante (1992) resulted in a guide for evaluating suitability of various proposed fish habitat structures for a wide range of morphological stream types. many of the protective measures presented in this chapter require evaluation. the response of fish and wildlife populations to changes in habitat is often difficult to predict with confidence. The need for access to the stream or shoreline and the effects of protection measures upon adjacent property and land uses should be analyzed. and gravel placement are for spawning habitat enhancement. stream geometry) has been successfully used to achieve grade control. Since a multitude of interrelated factors influence the productivity of streams. bankplaced materials. Damages to the environment can be limited by: • Using small equipment and hand labor. such as low cost or ease of construction. Control can be by natural or artificial means. Reconstructing stream channels to their historical stream type (i. and replacement costs are considered. gabions and reinforced concrete grade control structures. and aquatic requirements. U-shaped gravel traps. Minor protective measures can be installed without using contract labor or heavy equipment. access for equipment and crews at the site. • Limiting access. Other factors include the suitability of construction material for the use intended. durability of material. December 1996) . Effect upon resources and environmental values. In general.e. and adaptations needed to adjust designs to special conditions and the local environment. single wing deflector. and migration barrier. (210-vi-EFH. such as fish spawning or bird nesting periods.Chapter 16 Streambank and Shoreline Protection Fish habitat structures are commonly an integral part of stream protection measures. • Locating staging areas outside work area boundaries. medium stage check dam. log sill gravel traps. woody vegetative buffers. • Coordinating construction on a stream that involves more than one job or ownership. Special care should be given to consideration of terrestrial and aquatic habitat benefits of alternative types of protection and to maintenance needs on a site specific basis. such as aesthetics. the cost of labor and machinery. submerged shelter. However. bank cover.. half log cover. floating log cover. but applicability of habitat structures varies by classified stream type. and implementation to be done by a knowledgeable interdisciplinary team because precise construction techniques and costly construction materials may be required. (c) Design considerations for streambank protection (1) Channel grade The channel grade may need to be controlled before any permanent type of bank protection can be considered feasible unless the protection can be safely and economically constructed to a depth well below the anticipated lowest depth of bed scour. (10) Environmental data Environmental goals should be set early in the planning process to ensure that full consideration is given to ecological stability and productivity during the selection and design of streambank protection measures. The structures for rearing habitat enhancement include low stage check dam. Changes in channel alignment are not recommended unless the change is to reconstruct the channel to its former meander geometry. the allowance for freeboard should be based on sound judgment and experience. On smaller streams. Erosion or sedimentation may occur if this is not anticipated. Velocity changes can reduce available habitat or create physical barriers that restrict fish passage. the Manning’s n values selected should represent the stream condition after the channel has matured. Because an accurate method to determine freeboard requirements is not available for sloping revetments in critical zones. Straightening without extensive channel hardening does not eliminate a stream's tendency to meander. and the climb on sloping revetments may be appreciable. More substantial and permanent types of construction may be needed on curved channel sections because streambank failures at these vulnerable points could result in much greater damage than that along unobstructed straight reaches of channel. Because of major changes in hydraulic characteristics. Where the flow entering the section is transporting bedload. The design flood frequency should be compatible with the value or safety of the property or improvements being protected. and the sensitivity and value of ecological systems within the planning unit. Curved revetments are subjected to increased forces because of the secondary currents acting against them. For modified streams. which normally requires several years. December 1996) 16–7 . however. the minimum velocity should be that which will transport the entering bedload material through the section. and below the changed reach. and current direction changes. Under similar conditions. streambanks for channels having straight alignment generally require a continuous scour-resistant lining or revetment. Part 650 Engineering Field Handbook (4) Freeboard Freeboard should be provided to prevent overtopping of the revetment at curves and other points where high velocity flow contacts the revetment. the slope must be flat enough to prevent the lining material from sliding. the maximum velocity should be limited to that which is nonscouring on the least resistant material occurring in any appreciable quantity in the streambed and bank.Chapter 16 Streambank and Shoreline Protection (2) Discharge frequency Maximum floods are rarely used for design of streambank protection measures. (5) Alignment Changes in channel alignment affect the flow characteristics through. the protective measures can influence the velocity throughout the reach. The depth-areavelocity relationship of the upstream channel should be maintained through the protected reach. 1991). bar formations. To prevent scour by streamflow as the stream attempts to recreate its natural meander pattern. silt. most banks must be sloped to a stable grade before the lining is applied. (210-vi-EFH. In calculating these velocities. 1992). The minimum design velocity should also be compatible with the needs of the various fish species present or those targeted for recovery. and fine sand in suspension. wide channels most likely will not significantly change streamflow velocity. The discharge at this frequency is commonly used as a design discharge for stream restoration (Rosgen. Bankfull discharge (stream-forming flow) of natural streams tends to have a recurrence interval of 1 to 2 years based on the annual flood series (Leopold and Rosgen. For nonrigid lining. (3) Discharge velocities Where the flow entering the section to be protected carries only clay. the repair cost of the streambank protection. Further information on fish habitat is available in publications cited in the reference section. In these areas a potential supercritical velocity can set up waves. the 1to 2-year frequency discharge is also useful for design discharge because it is the flow that has the most impact upon the stability of the stream channel. above. An erosion hazard may often develop at both ends of the channel because of velocity increases. Alignment of the reach must also be carefully considered in designing protective measures. Streambank protection measures on large. the freeboard required for a sloping revetment is always greater than that for a vertical revetment. The minimum velocity should be that required to transport the suspended material. The size distribution of the streambed and bar material also should be determined. 1983) on gravelbed rivers. These measurements are important above and below the reconstruction reach under consideration as well as in the main tributary streams above the reach. Deep scour can be expected where construction is on an erodible streambed and high velocity currents flow adjacent to it. (210-vi-EFH. or well-vegetated stable sections. amplitude. piling should be driven to a depth equal to about twice the exposed height. its base or toe. and radius of curvature. This allows the rock forming the toe to settle in place if scour occurs. which at the time of installation will extend some distance out into the channel. This mattress will settle progressively as scour takes place. the sediment load (bedload and suspended) for storm and snowmelt runoff periods must frequently be determined before reconstruction. If this is not practical. it is anticipated that particles as large as the median diameter of the bed surface will be entrained by discharge equal to the bankfull stage (stream-forming flow) or less. To provide for a remaining embedment after scour. The sediment transport rate must be sufficient to prevent aggradation of the newly restored channel. the upstream and downstream ends of the revetment must be positioned well into a slack water area along the bank where bank erosion is not a problem. (9) Undermining Undermining or scouring of the foundation material by high velocity currents is a major cause of bank protection failure. because of the forces of flow. • Driving sheet piling to form a continuous protection for the revetment foundation. (10) Ends of revetment The location of the upstream and downstream ends of revetments must be selected carefully to avoid flanking by erosion. • Installing submerged vanes to control secondary currents. Wherever possible. In addition to protecting the lowest expected stable grade. Since most of these measures have direct impacts on aquatic habitat and other stream functions and values. (7) Sediment load and bed material To determine the potential for stream aggradation. • Installing toe deflector groins to deflect high velocity currents away from the toe of the revetment. additional depth must be provided to reach a footing that most likely will not be scoured out during floods or lose its stability through saturation. the revetment should tie into stable anchorage points. and a lower ratio may be needed in the design channel. As shown by studies in Colorado (Andrews. This information is used with appropriate shear stress equations to determine the size of material that would be entrained at bankfull discharge (stream-forming flow) for both the tributary streams and in the restored reach. and the crest or top. December 1996) . the settlement direction of the rock is not always straight down. • Installing a massive toe of heavy rock where excavation for a deep toe is not practical. protecting the revetment foundation.Chapter 16 Streambank and Shoreline Protection (6) Stream type and hydraulic geometry Stream rehabilitation should be considered in the context of the historically stable stream type and its geometry. The width-to-depth ratio of the stream being treated may be too high to transport the sediment load. However. If stream modification has caused shortened meander wavelength. Such piling should be securely anchored against lateral pressures. rock outcrops. (8) Protection against failure Measures should be designed to provide against loss of support at the revetment’s boundaries. 16–8 Part 650 Engineering Field Handbook Methods used to provide protection against undermining at the toe are: • Extending the toe trench down to a depth below the anticipated scour and backfilling with heavy rock. their use should be considered carefully when planning a streambank protection project. the stream being treated might be best stabilized by restoring the historical geometry. flexible mattress to the bottom of the revetment. such as bridge abutments. • Anchoring a heavy. This includes upstream and downstream ends. and other debris drifts that create secondary currents or deflect flow toward the banks may require selective removal or relocation in the stream channel. The entire plant structure does not always need to be dislodged when considering the removal of trees and snags. grading. and material delivery and placement should be accomplished in a manner that uses the smallest equipment feasible and minimizes disturbance of riparian vegetation. sediment bars. rooted stumps should be left in place to prevent erosion. and insects drop into the stream. such as fallen trees. trees. When planning streambank stabilization work. 16–2). (12) Vegetative systems Vegetative systems provide many benefits to fish and wildlife populations as well as increasing the streambank's resistance to erosive forces. lodged. a plan for debris removal should be developed in consultation with qualified fish and wildlife specialists. Fallen trees may be used to construct bank protection systems. In high velocity streams it may be necessary to remove floating debris selectively from flood-prone areas or anchor it so that it will not float back into the channel. Isolated or single logs that are embedded. Because logs and other woody debris are the major habitat-forming components in many stream systems.Chapter 16 Streambank and Shoreline Protection (11) Debris removal Streambank protection may require the selective removal or repositioning of debris. snags. twigs. or rooted in the channel and not causing flow problems should not be disturbed. Trees and other large vegetation are important to aquatic. provides habitat for wildlife and protection from predators. providing nutrients for aquatic life (fig. Leaves. flood plain drainage. Small accumulations of debris and sediment generally do not cause problems and should be left undisturbed. and removal should be done judiciously and with great care. Vegetation near the channel provides shade to help maintain suitable water temperature for fish. select access routes for equipment that minimize disturbance to the flood plain and riparian areas. Excavated material should be disposed of in such a way that it does not interfere with overbank flooding. aesthetic and riparian habitat systems. or other obstructions. Part 650 Engineering Field Handbook Sediment bars. December 1996) 16–9 . Figure 16–2 Vegetative system along streambank (210-vi-EFH. and contributes to aesthetic quality. or associated wetland hydrology. All debris removal. in straighter sections or at the inside of curves in the channel where velocities are low. should be used rather than annual grasses. • Vegetation acts as a buffer against the hydraulic forces and abrasive effect of transported materials. Woody vegetation may also be used to control undesirable access to the stream. • Dense vegetation on streambanks can induce sediment deposition. Vegetation assists in bank stabilization by trapping sediment. and climatic conditions of a particular site are desirable. habitat value. Aesthetics may also play an important role in selecting plants for certain areas. Providing watering facilities out of the channel (i. Exotic or introduced species should be used only if there is no alternative. which is seeded or planted as rooted stock. which tend to undercut them. is much less than that provided by structural elements. but do not directly stabilize the channel grade. or otherwise ensure that materials become established and self-sustaining. reducing tractive stresses acting on the bank. Such ramps should be located where the bank is not steep and. 16–10 Part 650 Engineering Field Handbook • Protection and maintenance requirements are often high during plant establishment. Protective measures reduce streambank erosion and prevent land losses and sediment damages. including the protection of woody streambank or shoreline vegetation from wave or current wave action. on the flood plain or terrace) for the livestock is often a preferred alternative to using ramps. vegetative protective measures. however. preferably those native to the area. soil bioengineering systems. They are often used in combination. or by overuse. Perennial grasses and forbes. cultivating too close to the banks. redirecting the flow. • Establishing plants in coarse gravely material may be difficult. such as soil bioengineering. can be used to stabilize the streambanks. Locally available erosion-resistant species that are suited to the soil.Chapter 16 Streambank and Shoreline Protection Although woody brush is preferable for habitat reasons. (d) Protective measures for streambanks Protective measures for streambanks can be grouped into three categories: vegetative plantings. if the channel is restored to a stable stream type. and holding soil. The boundary shear stress provided by vegetation. • Vegetation can redirect flow away from the bank. control disease. Vegetation protects streambanks in several ways: • Root systems help hold the soil particles together increasing bank stability. However. and structural measures.e. (1) Vegetative plantings Conventional plantings of vegetation may be used alone for bank protection on small streams and on locations having only marginal erosion. In many instances streambank erosion is accelerated by overgrazing. Vegetation should always be used behind revetments and jetties in the area where sediment deposition occurs. moisture. If the stream is the source of livestock drinking water. (210-vi-EFH. December 1996) . The visual impact. and other environmental effects of material removal or relocation must also be considered before performing any work. In either case the treated area should be protected by adequate streamside buffers and appropriate management practices. Considerations in using vegetation alone for protection include: • Conventional plantings require establishment time. and bank protection is not immediate. Use locally collected native species as a first priority. on the banks above baseflow. or it may be used in combination with structural measures in other situations. Many species of plants are suitable for streambank protection (see appendix 16B). • Vegetation may increase the hydraulic resistance to flow and reduce local velocities in small channels. • Establishing plants to prevent undercutting and bank sloughing in a section of bank below baseflow is often difficult. access can be provided by establishing a ramp down to the water. Woody vegetation. and on slopes protected by cellular blocks or similar type materials. • Maintenance may be needed to replace dead plants.. They should never be invasive species. suitable herbaceous ground cover can provide desirable bank protection in areas of marginal erosion. Associated emergent aquatic plants serve multiple functions. preferably. is used most successfully above baseflow on properly sloped banks and on the flood plain adjacent to the banks. and 16–3d). Suitable plant materials are listed in appendix 16B. As discussed in chapter 18 of this Engineering Field Handbook. The main construction materials are live cuttings from suitable plant species. living systems include brushmattresses. preferably in the spring. and live fascines. shade. which is the off season for many laborers. generally September to March. and create a more environmentally acceptable product. They should be installed for species diversification and to provide habitat cover and food for fish and wildlife. Rooted seedlings and rooted cuttings are excellent additions to soil bioengineering projects. the work is normally done in the dormant months. A steep undercut or slumping bank. 16–3c. or where unrooted cuttings are used with structural measures. Soil bioengineering is a system of living plant materials used as structural components. (210-vi-EFH. December 1996) 16–11 . Environmental benefits derived from woody vegetation include diverse and productive riparian habitats. branchpacking. They may also be identified in Field Office Technical Guides for specific site conditions or by contacting Plant Materials Centers. Under certain conditions. Major attractions of soil bioengineering systems are their natural appearance and function and the economy with which they can often be constructed.Chapter 16 Streambank and Shoreline Protection (2) Soil bioengineering systems Properly designed and constructed soil bioengineering systems have been used successfully to stabilize streambanks (figs. Species that root easily. joint plantings. Consult a plant materials specialist for guidance on plant selection. are required for measures. Optimum establishment is usually achieved shortly after earth work. enhance aesthetics. Ideally plant materials should come from local ecotypes and genetic stock similar to that within the vicinity of the stream. Although soil bioengineering systems are suitable for most sites. In addition. Soil bioengineering systems normally use unrooted plant parts in the form of cut branches and rooted plants. 16–3a. For streambanks. such as live fascines and live staking. such as willow. for example. Adapted types of woody vegetation (shrubs and trees) are initially installed in specified configurations that offer immediate soil protection and reinforcement. live stakes. vegetated geogrids. they are most successful where installed in sunny locations and constructed during the dormant season. soil bioengineering installations work well in conjunction with structures to provide more permanent protection and healthy function. and improvements in aesthetic value and water quality. soil bioengineering systems create resistance to sliding or shear displacement in a streambank as they develop roots or fibrous inclusions. Species must be appropriate for the intended use and adapted to the site's climate and soil conditions. organic additions to the stream. cover for fish. 16–3b. Some of the most common and useful soil bioengineering structures for restoration and protection of streambanks are described in the following sections. may require grading to a 3:1 or flatter slope. Part 650 Engineering Field Handbook Many sites require some earthwork before soil bioengineering systems are installed. Winooski River. Winooski River. Vermont. Winooski River. Vermont.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Figure 16–3a Eroding bank. 1941 Figure 16–3d Soil bioengineering system. September 1938 Figure 16–3c Three years after installation of soil bioengineering practices. June 1938 Figure 16–3b Bank shaping prior to installing soil bioengineering practices. June 1993 (55 years after installation) 16–12 (210-vi-EFH. December 1996) . Vermont. December 1996) Note: Rooted/leafed condition of the living plant material is not representative of the time of installation. Most willow species root rapidly and begin to dry out a bank soon after installation. • Stabilize intervening areas between other soil bioengineering techniques. 16–13 . .... • Can be used to peg down and enhance the performance of surface erosion control materials. • Appropriate technique for repair of small earth slips and slumps that frequently are wet. If correctly prepared. Figure 16–4 Live stake details . the live stake will root and grow (fig.. such as live fascines.. Cross section Not to scale Streambank 2 to 3 feet 90° Dead stout stake 2 to 3 feet (triangular spacing) Stream-forming flow Baseflow Erosion control fabric Live cutting 1/2 to 1 1/2 inches in diameter Streambed Toe protection Geotextile fabric (210-vi-EFH. and an inexpensive method is needed.. 16–6).. Part 650 Engineering Field Handbook Applications and effectiveness • Effective streambank protection technique where site conditions are uncomplicated... . construction time is limited........ and placed.Chapter 16 Streambank and Shoreline Protection (i) Live stakes—Live staking involves the insertion and tamping of live. 16–4 and 16–5). .. . handled.... ... • Produce streamside habitat. A system of stakes creates a living root mat that stabilizes the soil by reinforcing and binding soil particles together and by extracting excess soil moisture..... rootable vegetative cuttings into the ground (figs. • Enhance conditions for natural colonization of vegetation from the surrounding plant community... Live material preparation • The materials must have side branches cleanly removed with the bark intact. and soil should be firmly packed around it after installation. • The live stakes should be installed 2 to 3 feet apart using triangular spacing. • Do not split the stakes during installation. • The basal ends should be cut at an angle or point for easy insertion into the soil.Chapter 16 Streambank and Shoreline Protection Construction guidelines Live material sizes—The stakes generally are 0. Stakes that split should be removed and replaced. • Tamp the stake into the ground with a dead blow hammer (hammer head filled with shot or sand). tree-type willow species are placed on the inside curves of point bars where more inundation occurs. 16–14 Part 650 Engineering Field Handbook • Placement may vary by species. The density of the installation will range from 2 to 4 stakes per square yard. The installation may be started at any point on the slope face. • An iron bar can be used to make a pilot hole in firm soil. • Tamp the live stake into the ground at right angles to the slope and diverted downstream. • Materials should be installed the same day that they are prepared.5 to 1. For example. (210-vi-EFH. along many western streams. • The buds should be oriented up. The specific site requirements and available cutting source determine sizes. Installation • Erosion control fabric should be placed on slopes subject to erosive inundation. The top should be cut square.5 inches in diameter and 2 to 3 feet long. • Four-fifths of the length of the live stake should be installed into the ground. while shrub willow species are planted on outside curves where the inundation period is minimal. December 1996) . Site variations may require slightly different spacing. Sotir & Associates photo) Figure 16–6 Growing live stake (210-vi-EFH.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Figure 16–5 Prepared live stake (Robbin B. December 1996) 16–15 . . Each length should be cut again diagonally across the 4-inch face to make two stakes from each length (fig 16–8).. Secure the fabric. leaving 3 inches to protrude above the top of the ground (fig.Soils . Installation • Prepare the live fascine bundle and live stakes immediately before installation. Figure 16–9c shows an established live fascine system 2 years after installation is completed. The top of the live fascine should be slightly visible when the installation is completed. • Beginning at the base of the slope... 16–16 (210-vi-EFH. Live material sizes and preparation • Cuttings tied together to form live fascine bundles normally vary in length from 5 to 10 feet or longer..Chapter 16 Part 650 Engineering Field Handbook Streambank and Shoreline Protection (ii) Live fascines—Live fascines are long bundles of branch cuttings bound together in cylindrical structures (fig. 16–9b). Where possible. Dead stout stakes used to secure the live fascines should be 2. Applications and effectiveness • Apply typically above bankfull discharge (stream-forming flow) except on very small drainage area sites (generally less than 2.. sound lumber should be used. • Excavate trenches up the slope at intervals specified in table 16–1.. Only new.. 16–7)... • Serve to facilitate drainage where installed at an angle on the slope. • Place the live fascine into the trench (fig. December 1996) . • Capable of trapping and holding soil on a streambank by creating small dam-like structures. • Install jute mesh. 16–9a). depending on site conditions and limitations in handling. When properly installed.. • Effective stabilization technique for streambanks. Extra stakes should be used at connections or bundle overlaps. Tamp the live stakes below and against the bundle between the previously installed dead stout stakes. • Protect slopes from shallow slides (1 to 2 foot depth). dig a trench on the contour approximately 10 inches wide and deep. coconut netting. • Place long straw and annual grasses between rows. and any stakes that shatter upon installation should be discarded. Place moist soil along the sides of the bundles.Erosive Non-erosive Fill (feet) (feet) (feet) 3:1 or flatter 3–5 5–7 3 – 5 1/ Steeper than 3:1 (up to 1:1) 3 1/ 3–5 2/ 1/ Not recommended alone.. • Enhance conditions for colonization of native vegetation by creating surface stabilization and a microclimate conducive to plant growth. 2 by 4 lumber.. • Offer immediate protection from surface erosion. Stagger the cuttings in the bundles so that tops are evenly distributed throughout the length of the uniformly sized live fascine. Inert materials—String used for bundling should be untreated twine.. 2/ Not a recommended system. with all of the growing tips oriented in the same direction.000 acres). • Live stakes are generally installed on the downslope side of the bundle. place one or two rows over the top of the slope.. thus reducing the slope length into a series of shorter slopes. or other acceptable erosion control fabric..... untreated.5-foot long.5 feet long. They should be placed in shallow contour trenches on dry slopes and at an angle on wet slopes to reduce erosion and shallow sliding. that root easily and have long. this system does not cause much site disturbance. • The completed bundles should be 6 to 8 inches in diameter. Table 16–1 Live fascine spacing Slope steepness . • Drive the dead stout stakes directly through the live fascine. • Live stakes should be 2.. Leave the top of the dead stout stakes flush with the installed bundle. such as young willows or shrub dogwoods.. Construction guidelines Live materials—Cuttings must be from species. straight branches. .......Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook .. .... .... .... ......... . December 1996) 16–17 . Dead stout stake (2. .... Figure 16–7 Live fascine details Top of live fascine slightly exposed after installation Cross section Not to scale Moist soil backfill Prepared trench Erosion control fabric & seeding Stream-forming flow Baseflow Streambed Live fascine bundle Live stake (2...... .. .to 3-foot spacing between dead stout stakes) Geotextile fabric Toe protection Note: Rooted/leafed condition of the living plant material is not representative of the time of installation.to 3-foot spacing along bundle) Live branches (stagger throughout bundle) Bundle (6 to 8 inches in diameter) Twine (210-vi-EFH. Sotir & Associates photo) . Sotir & Associates photo) (210-vi-EFH. Sotir & Associates photo) 2 1/2' Figure 16–9c 2" by 4" lumber Saw a 2" by 4" diagonally to produce two dead stout stakes Not to scale Figure 16–9a 16–18 Placing live fascines (Robbin B.Chapter 16 Streambank and Shoreline Protection Figure 16–8 Preparation of a dead stout stake Figure 16–9b Part 650 Engineering Field Handbook Installing live stakes in live fascine system (Robbin B. December 1996) An established 2-year-old live fascine system (Robbin B. • Place an initial layer of living branches 4 to 6 inches thick in the bottom of the hole between the vertical stakes. (210-vi-EFH. while roots spread throughout the backfill and surrounding earth to form a unified mass. Set them 1 to 1. • Rapidly establishes a vegetated streambank. and 16–11c). the branchpacking system becomes increasingly effective in retarding runoff and reducing surface erosion. • Each layer of branches must be followed by a layer of compacted soil to ensure soil contact with the branches. drive the wooden stakes vertically 3 to 4 feet into the ground.5 feet apart. • Water must be controlled or diverted if the original streambank damage was caused by water flowing over the bank. Installation • Starting at the lowest point. and perpendicular to the slope face (fig. • Live branches serve as tensile inclusions for reinforcement once installed. As plant tops begin to grow. December 1996) 16–19 . Inert materials—Wooden stakes should be 5 to 8 feet long and made from 3. • Produces a filter barrier that prevents erosion and scouring from streambank or overbank flow. If this is not done. depending upon the depth of the particular slump or hole being repaired. • Subsequent layers of branches are installed with the basal ends lower than the growing tips of the branches. • Typically branchpacking is not effective in slump areas greater than 4 feet deep or 4 feet wide.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook (iii) Branchpacking—Branchpacking consists of alternating layers of live branches and compacted backfill to repair small localized slumps and holes in streambanks (figs. Some of the basal ends of the branches should touch the undisturbed soil at the back of the hole. 16–10). erosion will most likely occur on either or both sides of the new branchpacking installation. Trapped sediment refills the localized slumps or hole. • Enhances conditions for colonization of native vegetation.5 to 2 inches in diameter. • The final installation should conform to the existing slope.to 4-inch diameter poles or 2 by 4 lumber. They should be placed in a criss-cross configuration with the growing tips generally oriented toward the slope face. Construction guidelines Live materials—Live branches may range from 0. 16–11b. • Provides immediate soil reinforcement. 16–11a. 16–10. Branches should protrude only slightly from the filled installation. Applications and effectiveness • Effective and inexpensive method to repair holes in streambanks that range from 2 to 4 feet in height and depth. They should be long enough to touch the undisturbed soil of the back of the trench and extend slightly from the rebuilt streambank. . driven 3 to 4 feet into undisturbed soil) Baseflow Streambed 1 to 1 1/2 feet Geotextile fabric Toe protection Note: Root/leafed condition of the living plant material is not representative of the time of installation .. December 1996) ...... 16–20 (210-vi-EFH.. 2 by 4 lumber..... ..... .to 2-inch diameter) Compacted fill material Stream-forming flow Wooden stakes (5.......... . . depth 4' Max. depth 4' Streambank after scour Live branches (1/2..Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook ..... . .to 8-foot long. plantings or soil bioengineering systems Max. Figure 16–10 Branchpacking details Cross section Not to scale Existing vegetation.. . Chapter 16 Figure 16–11a Streambank and Shoreline Protection Live branches installed in criss-cross configuration (Robbin B. December 1996) 16–21 . Sotir & Associates photo) (210-vi-EFH. Sotir & Associates Figure 16–11b photo) Figure 16–11c Part 650 Engineering Field Handbook Each layer of branches is followed by a layer of compacted soil (Robbin B. Sotir & Associates photo) A growing branchpacking system (Robbin B. Fill this area with rocks 2 to 3 inches in diameter. • Function immediately after high water to rebuild the bank. and 16–13c). • Produce rapid vegetative growth. 16–12. • The final installation should match the existing slope. Applications and effectiveness • Used above and below stream-forming flow conditions. • Useful in restoring outside bends where erosion is a problem.Chapter 16 Streambank and Shoreline Protection (iv) Vegetated geogrids—Vegetated geogrids are similar to branchpacking except that natural or synthetic geotextile materials are wrapped around each soil lift between the layers of live branch cuttings (figs. • Capture sediment. • Continue this process of excavated trenches with alternating layers of cuttings and geotextile wraps until the bank is restored to its original height. • Benefits are similar to those of branchpacking. • Beginning at the stream-forming flow level. 16–13a. • This system should be limited to a maximum of 8 feet in total height. They should be 4 to 6 feet long.to 8-inch layer of live branch cuttings on top of the rock-filled geogrid with the growing tips at right angles to the streamflow. • Can be complex and expensive. Inert materials—Natural or synthetic geotextile material is required. Place the geotextile in the trench. Branch cuttings should protrude only slightly from the geotextile wraps. The basal ends of branch cuttings should touch the back of the excavated slope. • Cover this layer of cuttings with geotextile leaving an overhang. • The system must be built during low flow conditions. well-reinforced streambank.000 acres) with stable streambeds. Place a 12-inch layer of soil suitable for plant growth on top of the geotextile before compacting it to ensure good soil contact with the branches. including the 2 to 3 feet below the bed. which rapidly rebuilds to further stabilize the toe of the streambank. • Enhance conditions for colonization of native vegetation. December 1996) . The length should not exceed 20 feet for any one unit along the stream. place a 6. Construction guidelines Live materials—Live branch cuttings that are brushy and root readily are required. • Produce a newly constructed. 16–22 Part 650 Engineering Field Handbook (210-vi-EFH. Installation • Excavate a trench that is 2 to 3 feet below streambed elevation and 3 to 4 feet wide. leaving a foot or two overhanging on the streamside face. An engineering analysis should determine appropriate dimensions of the system. 16–13b. Wrap the overhanging portion of the geotextile over the compacted soil to form the completed geotextile wrap. • Drainage areas should be relatively small (generally less than 2. but a vegetated geogrid can be placed on a 1:1 or steeper slope. . Install additional vegetation such as live stakes... . December 1996) 16–23 . etc.. ..Chapter 16 Figure 16–12 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Vegetated geogrid details Dead stout stake used to secure geotextile fabric Cross section Not to scale ......... . ......... Eroded streambank Compacted soil approximately 1-foot thick Live cuttings Geotextile fabric Height varies 8 foot maximum Stream-forming flow Baseflow Streambed Rock fill 2 to 3 feet Note: Rooted/leafed condition of the living plant material is not representative of the time of installation.. .... . . 3 to 4 fe et (210-vi-EFH. . rooted seedlings. .. . .... ......... December 1996) . Sotir & Associates photo) Part 650 Engineering Field Handbook A vegetated geogrid immediately after installation (Robbin B. Sotir & Associates photo) Figure 16–13c 16–24 Vegetated geogrid 2 years after installation (Robbin B. Sotir & Associates photo) (210-vi-EFH.Chapter 16 Figure 16–13a Streambank and Shoreline Protection A vegetated geogrid during installation Figure 16–13b (Robbin B. excavate 2 to 3 feet below the existing streambed until a stable foundation 5 to 6 feet wide is reached. • Useful where space is limited and a more vertical structure is required. while established vegetation provides long-term stability. Each course of the live cribwall is placed in the same manner and secured to the preceding course with nails or reinforcement bars. The lengths will vary with the size of the crib structure. December 1996) 16–25 . • Provides excellent habitat. place live branch cuttings on the backfill perpendicular to the slope. 16–15b. • Place rock fill in the openings in the bottom of the crib structure until it reaches the approximate existing elevation of the streambed. • Should be tilted back or battered if the system is built on a smooth. • Can be complex and expensive.5 inches in diameter and long enough to reach the back of the wooden crib structure. Ensure that the basal ends of some of the cuttings contact undisturbed soil at the back of the cribwall. Once the live cuttings root and become established. • Place the first course of logs or timbers at the front and back of the excavated foundation. Follow each layer of branches with a layer of compacted soil. Applications and effectiveness • Effective on outside bends of streams where strong currents are present. (210-vi-EFH. especially in outside stream meanders. the subsequent vegetation gradually takes over the structural functions of the wood members (fig. • The length of any single constructed unit should not exceed 20 feet. then cover the cuttings with backfill and compact. Large nails or rebar are required to secure the logs or timbers together. 16–15a. including the section below the streambed. approximately 4 to 5 feet apart and parallel to the slope contour.Chapter 16 Streambank and Shoreline Protection (v) Live cribwall—A live cribwall consists of a boxlike interlocking arrangement of untreated log or timber members. • Effective in locations where an eroding bank may eventually form a split channel. and 16–15c). • When the cribwall structure reaches the existing ground elevation. 16–14). An engineering analysis should determine appropriate dimensions of the system. • The live cribwall structure. • Appropriate at the base of a slope where a low wall may be required to stabilize the toe of the slope and reduce its steepness. Inert materials—Logs or timbers should range from 4 to 6 inches in diameter or dimension. • Place the next course of logs or timbers at right angles (perpendicular to the slope) on top of the previous course to overhang the front and back of the previous course by 3 to 6 inches. Construction guidelines Live materials—Live branch cuttings should be 0. The structure is filled with suitable backfill material and layers of live branch cuttings that root inside the crib structure and extend into the slope. • Place the first layer of cuttings on top of the rock material at the baseflow water level. and change the rock fill to soil fill capable of supporting plant growth at this point. evenly sloped surface. • Live branch cuttings should be placed at each course to the top of the cribwall structure with growing tips oriented toward the slope face. • Appropriate above and below water level where stable streambeds exist. • Excavate the back of the stable foundation (closest to the slope) 6 to 12 inches lower than the front to add stability to the structure.5 to 2. should not exceed a maximum height of 7 feet. • Maintains a natural streambank appearance. Part 650 Engineering Field Handbook Installation • Starting at the base of the streambank to be treated. • Provides immediate protection from erosion. • Supplies effective bank erosion control on fast flowing streams. In some cases it is necessary to place rocks in front of the structure for added toe support. Place the basal ends of the remaining live branch cuttings so that they reach to undisturbed soil at the back of the cribwall with growing tips protruding slightly beyond the front of the cribwall (figs. .... 16–26 (210-vi-EFH.. ............. ...Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook ... December 1996) .... ..... .. .. Figure 16–14 Live cribwall details Existing vegetation....... .... ... plantings or soil bioengineering systems Cross section Not to scale Erosion control fabric Compacted fill material Stream-forming flow Baseflow 3 to 4 feet Live branch cuttings Streambed 2 to 3 feet Rock fill 4 to 5 feet Note: Rooted/leafed condition of the living plant material is not representative of the time of installation.. Chapter 16 Streambank and Shoreline Protection Figure 16–15a Pre-construction streambank conditions Figure 16–15c An established live cribwall system Figure 16–15b (210-vi-EFH. December 1996) Part 650 Engineering Field Handbook A live cribwall during installation 16–27 . .. .... • Place the stakes in a random configuration. joint plantings create a living root mat in the soil base upon which the rock has been placed. A steel rod or hydraulic probe may be used to prepare a hole through the riprap.. • Over time. The basal ends of the material must extend into the backfill or undisturbed soil behind the riprap. Installation • Tamp live stakes into the openings of the rock during or after placement of riprap.. They should be 1... .... Alternatively.Chapter 16 Streambank and Shoreline Protection (vi) Joint planting—Joint planting or vegetated riprap involves tamping live stakes into joints or open spaces in rocks that have been previously placed on a slope (fig 16–16). • Provides immediate protection and is effective in reducing erosion on actively eroding banks.. These root systems bind or reinforce the soil and prevent washout of fines between and below the rock..5 inches or larger in diameter and sufficiently long to extend well into soil below the rock surface.. 16–17a... and 16–17c). Figure 16–16 Joint planting details Cross section Not to scale Stream-forming flow Baseflow Streambed Riprap Dead stout stake used to secure geotextile fabric Live stake 16–28 (210-vi-EFH... Part 650 Engineering Field Handbook Construction guidelines Live material sizes—The stakes must have side branches removed and bark intact. • Dissipates some of the energy along the streambank... Applications and effectiveness • Useful where rock riprap is required or already in place.. . the stakes can be tamped into place at the same time that rock is being placed on the slope face. December 1996) . • Roots improve drainage by removing soil moisture. 16–17b... • Orient the live stakes perpendicular to the slope with growing tips protruding slightly from the finished face of the rock (figs.. December 1996) 16–29 . Sotir & Associates photo) An established joint planting system (Robbin B.Chapter 16 Figure 16–17a Figure 16–17c Streambank and Shoreline Protection Live stake tamped into rock joints (joint planting) (Robbin B. Sotir & Associates photo) (210-vi-EFH. Sotir & Associates photo) Figure 16–17b Part 650 Engineering Field Handbook An installed joint planting system (Robbin B. near the streamforming flow stage. • Useful on steep. but leave the top surface of the brushmattress and live fascine installation slightly exposed. fast-flowing streams. • Place live fascines in the prepared trench over the basal ends of the branches. (210-vi-EFH. • Fill voids between brushmattress and live fascine cuttings with thin layers of soil to promote rooting. and branch cuttings installed to cover and stabilize streambanks (figs. as previously described in this chapter. Construction guidelines Live materials—Branches 6 to 9 feet long and approximately 1 inch in diameter are required. Live stakes and live fascines are previously described in this chapter. • Captures sediment during flood conditions. December 1996) . • Install an even mix of live and dead stout stakes at 1-foot depth over the face of the graded area using 2-foot square spacing. Inert materials—Untreated twine for bundling the live fascines and number 16 smooth wire are needed to tie down the branch mattress. They must be flexible to enable installations that conform to variations in the slope face. protective cover over the streambank. • Place branches in a layer 1 to 2 branches thick vertically on the prepared slope with basal ends located in the previously excavated trench. • Stretch No. live fascines. Dead stout stakes to secure the live fascines and brushmattress in place. excavate a trench on the contour large enough to accommodate a live fascine and the basal ends of the branches. • Prepare live stakes and live fascine bundles immediately before installation. 16–19a through 16–19d). • Beginning at the base of slope. Applications and effectiveness • Forms an immediate. Application typically starts above stream-forming flow conditions and moves up the slope.Chapter 16 Streambank and Shoreline Protection (vii) Brushmattress—A brushmattress is a combination of live stakes. 16 smooth wire diagonally from one dead stout stake to another by tightly wrapping wire around each stake no closer than 6 inches from its top. • Tamp and drive the live and dead stout stakes into the ground until branches are tightly secured to the slope. 16–30 Part 650 Engineering Field Handbook Installation • Grade the unstable area of the streambank uniformly to a maximum steepness of 3:1. • Enhances conditions for colonization of native vegetation. 16–18. • Rapidly restores riparian vegetation and streamside habitat. • Drive dead stout stakes directly through into soil below the live fascine every 2 feet along its length. ..... ... . ..Chapter 16 Figure 16–18 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Brushmattress details Live and dead stout stake spacing 2 feet o.. ..... ... Minimum length 2 1/2 feet... . Dead stout stake Wire secured to stakes Brush mattress Note: Rooted/leafed condition of the living plant material is not representative at the time of installation.c. ... Branch cuttings 16 gauge wire Live stake Stream-forming flow Baseflow Streambed Live fascine bundle Live stake Geotextile fabric Dead stout stake driven on 2-foot centers each way. .. December 1996) 16–31 ........ Cross section Not to scale ..... 2 ft (210-vi-EFH...... Sotir & Associates An installed brushmattress system (Robbin B. Sotir & Associates photo) Figure 16–19d photo) 16–32 Part 650 Engineering Field Handbook Brushmattress system 2 years after installation (Robbin B.Chapter 16 Figure 16–19a Streambank and Shoreline Protection Brushmattress during installation Figure 16–19b (Robbin B. December 1996) . Sotir & Associates photo) (210-vi-EFH. Sotir & Associates photo) Figure 16–19c Brushmattress system 6 months after installation (Robbin B. Pilings can be used in lieu of earth anchors in the bank if they can be driven well below the point of maximum bed scour. • Use trees that have a trunk diameter of 12 inches or larger. Applications and effectiveness • Uses inexpensive. and 16–21b). The best type are those that have a brushy top and durable wood. stream jetties. The required cable size and anchorage design are dependent upon many variables and should be custom designed to fit specific site conditions. (210-vi-EFH. • Captures sediment and enhances conditions for colonization of native species. 16–20. • Has self-repairing abilities following damage after flood events if used in combination with soil bioengineering techniques. log. which are buried in the bank (figs. December 1996) 16–33 . • Not appropriate near bridges or other structures where there is high potential for downstream damage if the revetment dislodges during flood events. depending on the climate and durability of tree species used. piling revetments with wire or geotextile fencing. • May require periodic maintenance to replace damaged or deteriorating trees. 16–21a. rootwad and boulder revetments. or beech. • Attach the trunks by cables to anchors set in the bank.Chapter 16 Streambank and Shoreline Protection (4) Structural measures Structural measures include tree revetments. • May be damaged in streams where heavy ice flows occur. dormant post plantings. • Use vegetative plantings or soil bioengineering systems within and above structures to restore stability and establish a vegetative community. and gabions. piling revetments with slotted fencing. hard maple. readily available materials to form semi-permanent protection. Part 650 Engineering Field Handbook Construction guidelines • Lay the cabled trees along the bank with the basal ends oriented upstream. Tree species that will withstand inundation should be staked in openings in the revetment below stream-forming flow stage. jacks or jack fields. • Has a limited life and may need to be replaced periodically. • Overlap the trees to ensure continuous protection to the bank. rock riprap. (i) Tree revetment—A tree revetment is constructed from whole trees (except rootwads) that are usually cabled together and anchored by earth anchors. oak. stream barbs. such as douglas fir. ........ .. plantings or soil bioengineering systems . ..... .Chapter 16 Figure 16–20 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Tree revetment details Plan view Not to scale w Flo Piling may be substituted for earth anchors Existing vegetation.. December 1996) . .) Two-thirds of bank height covered Stream-forming flow Second row applied Cross section Not to scale Baseflow Bank toe Earth anchors 6 feet deep 16–34 (210-vi-EFH. Stabilize streambank to top of slope where appropriate Earth anchors (8-inch dia... by 4-foot min. 2 years after installation (210-vi-EFH.Chapter 16 Streambank and Shoreline Protection Figure 16–21a Tree revetment system with dormant posts Figure 16–21b Tree revetment system with dormant posts. December 1996) Part 650 Engineering Field Handbook 16–35 . and boulders selectively placed in and on streambanks (figs. December 1996) . . and boulder revetment details (adapted from Rosgen 1993—Applied fluvial geomorphology short course) Existing vegetation. . . • Should be used in combination with soil bioengineering systems or vegetative plantings to stabi- .... shelters for insects and other fish food organisms. 16–22 and 16–23). rootwads.. substrate for aquatic organisms. • Will tolerate high boundary shear stress if logs and rootwads are well anchored. . These revetments can provide excellent overhead cover. Several of these combinations are described in Flosi and Reynolds (1991).. rootwad.. resting areas.......to 12-foot Length Stream-forming flow Rootwad Baseflow Streambed Thalweg channel Diameter of log = 16-in min... Boulder 1 1/2 times diameter of log Footer log 16–36 (210-vi-EFH.. . Rosgen (1992) and Berger (1991). rootwad and boulder revetments— These revetments are systems composed of logs.. • Suited to streams where fish habitat deficiencies exist.. and increased stream velocity that results in sediment flushing and deeper scour pools.... plantings or soil bioengineering systems Cross section Not to scale 8...Chapter 16 Streambank and Shoreline Protection (ii) Log. . . Figure 16–22 Log. Part 650 Engineering Field Handbook Applications and effectiveness • Used for stabilization and to create instream structures for improved fish rearing and spawning habitat • Effective on meandering streams with out-ofbank flow conditions....... but at a minimum one and one-half the log diameter. • Use rootwads with numerous root protrusions and 8. • Use boulders to anchor the footer log against flotation. CO (Rosgen. Forest Service publication. Cable and anchors may also be used in combination with boulders and rebar. Anchor rebar to provide maximum pull out resistance. December 1996) 16–37 . • Drive or trench and place rootwads into the streambank so that the tree's primary brace roots are flush with the streambank. • Enhance diversity of riparian corridor when used in combination with soil bioengineering systems.to 12-foot long boles. such as cottonwood or willow. or other upland methods at the top of the bank. live stakes. They should have an irregular surface. • Place the footer log to the expected scour depth at a slight angle away from the direction of the stream flow. • Have limited life depending on climate and tree species used. Revetments may need eventual replacement if natural colonization does not take place or soil bioengineering methods are not used in combination. bare root. They can include live stakes and dormant post plantings in the openings of the revetment below stream-forming flow stage. Some species. Rootwad. boulder. logs can be pinned into gravel and rubble substrate with 3/4-inch rebar 54 inches or longer. often sprout and accelerate natural colonization. Wildland hydrology) (210-vi-EFH. Chapter 16 only presents construction guidelines for a combination log. Stream Habitat Improvement Handbook. • Boulders should be as large as possible.S. Construction guidelines Numerous individual organic revetments exist and many are detailed in the U. and boulder revetment. • Use logs over 16 inches in diameter that are crooked and have an irregular surface.Chapter 16 Streambank and Shoreline Protection lize the upper bank and ensure a regenerative source of streambank vegetation. • Backfill and combine vegetative plantings or soil bioengineering systems behind and above rootwad. and willow transplant revetment system. If boulders are not available. Weminuche River. rootwad. Figure 16–23 Part 650 Engineering Field Handbook • Install a footer log at the toe of the eroding bank by excavating trenches or driving them into the bank to stabilize the slope and provide a stable foundation for the rootwad. Place the rootwads at a slight angle toward the direction of the streamflow. 16–24. Willows and poplars have demonstrated high success rates. non-gravely streams where ice damage is not a problem. • Place two or more rows of posts spaced 2 to 4 feet apart using square or triangular spacing. • Supplement the installation with appropriate soil bioengineering systems or. • Insert one-half to two-thirds of the length of post below the ground line. 16–25a.. . Taper the basal end of the post for easier insertion into the ground.. 16–25c). rooted plants. • Can be installed by a variety of methods including water jetting or mechanized stingers to form planting holes or driving the posts directly with machine mounted rams. • Reduce stream velocities and causes sediment deposition in the treated area.. Make sure posts are installed pointing up.. • Unsuccessfully rooted posts at spacings of about 4 feet can provide some benefits by deflecting higher streamflows and trapping sediment. • Install posts into the eroding bank at or just above the normal waterline. • Are self-repairing. Applications and effectiveness • Well suited to smaller. December 1996) .. Dormant post details . • Enhance conditions for colonization of native species. At least the bottom 12 inches of the post should be set into a saturated soil layer. • Avoid excessive damage to the bark of the posts.Chapter 16 Streambank and Shoreline Protection (iii) Dormant post plantings—Dormant post plantings form a permeable revetment that is constructed from rootable vegetative material placed along streambanks in a square or triangular pattern (figs. where appropriate. For example. Cross section Not to scale Dormant posts Existing vegetation. 16–25b.. • Cut live posts approximately 7 to 9 feet long and 3 to 5 inches in diameter. posts damaged by beaver often develop multiple stems. • Quickly re-establishe riparian vegetation. plantings or soil bioengineering systems Streambank Stream-forming flow 2:1 to 5:1 slope 5 ft Baseflow Streambed 2 ft 2 to 4 feet triangular spacing 16–38 Part 650 Engineering Field Handbook (210-vi-EFH.. • Can be used in combination with soil bioengineering systems. Figure 16-24 Construction guidelines • Select a plant species appropriate to the site conditions.. Chapter 16 Figure 16–25a Streambank and Shoreline Protection Pre-construction streambank conditions Figure 16–25b (Don Roseboom photo) Figure 16–25c Part 650 Engineering Field Handbook Installing dormant posts (Don Roseboom photo) Established dormant post system (Don Roseboom photo) (210-vi-EFH. December 1996) 16–39 . Fill the row space with rock and brush. (210-vi-EFH. Attach concrete blocks or other suitable weights at regular intervals to cause the fence to settle in a vertical position along the face of the pilings after scouring occurs. or pipe. habitat damage caused by driving or installing pilings with water jets. 16–26). such as timbers. swimming. • Is easily damaged by ice flows or heavy flood debris and should not be used where these conditions occur. December 1996) . logs. • Place brush behind the piling to increase the system's effectiveness. railroad rails. • Additional rows of pilings may be installed at higher elevations on the streambank if required to protect the bank and if using vegetation or other methods is not practical. extend the woven wire or geotextile material horizontally toward the center of the streambed for a distance at least equal to the anticipated depth of scour.Chapter 16 Streambank and Shoreline Protection (iv) Piling revetment with wire or geotextile fencing—Piling revetment is a continuous single or double row of pilings with a facing of woven wire or geogrid material (fig. drive pilings 6 to 8 feet apart to a depth approximately half their length and below the point of maximum scour. The space between double rows of pilings is filled with rock and brush. the piling should be driven to refusal or to a depth of at least half the length of the piling. 16–40 Part 650 Engineering Field Handbook Installation • Beginning at the base of the streambank. may be used for pilings. rafting. • Double row piling revetment is typically constructed with 5 feet between rows. The purpose of this material is to collect debris while serving as a permeable wall to reduce velocities on the streambank. Where piling revetments extend for several hundred feet in length. • Do not use where the stream has fish or an abundance of riparian wildlife. Applications and effectiveness • Particularly suited to streams where water next to the bank is more than 3 feet deep. If the streambed is firm and not subject to appreciable scour. near stream-forming flow stage. • Application is limited to a flow depth (and height of piling) of 6 feet. Logs should have a diameter sufficiently large to permit driving to the required depth. • Do not use without careful analysis of its longterm effects upon aesthetics. This reduces currents developing between the streambank and the revetment. Avoid material that may produce toxicity effects in aquatic ecosystems. • If the streambed is subject to scour. • More economical than riprap construction in deep water because it eliminates the need to build a stable foundation under water for holding the riprap in place. • Fasten a heavy gauge of woven wire or geotextile material to the stream side of the pilings to form a fence. and possible dangers for recreational uses (boating. changes in flows where large amounts of debris will be collected. Construction guidelines Inert materials—Used material. install permeable groins or tiebacks of brush and rock at right angles to the revetment at 50 foot intervals. or wading). .... ........to 12-in dia..... . December 1996) 16–41 ... .. ...... Figure 16–26 Piling revetment details Front elevation Heavy woven wire or geogrid fencing Piling Not to scale 6 to 8 feet Stream-forming flow Baseflow Streambed Weight Existing vegetation. ... plantings or soil bioengineering systems Cross section Not to scale Piling (8....Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook ...) Heavy woven wire or geogrid fencing Streambank 5 to 6 feet Stream-forming flow Baseflow Sloped bank Brush Concrete block weight Equal to or greater than height above ground Streambed (210-vi-EFH.... Figure 16–27 Part 650 Engineering Field Handbook Slotted board fence details (double fence option) .. . plantings or soil bioengineering systems Cross section Not to scale 5 ft.. Variations include different fence heights.. should not be used where these conditions occur. • Should not be constructed higher than 3 feet without an engineering analysis to determine sizes of the structural members.. . ...... . stream velocity. . • Can withstand a relatively high velocity attack force and.. December 1996) .... and use of woven wire in place of timber boards. .. .. . • Usually complex and expensive. . .... therefore.. double rows of slotted fence.Chapter 16 Streambank and Shoreline Protection • May be vulnerable to damage by ice or heavy flood debris... . and sediment load. Piling Boards Equal to or greater than height above ground (210-vi-EFH. 16–27 and 16–28). .. can be installed in sharper curves than jacks or other systems. The size and spacing of pilings.. .. .. Applications and effectiveness • Most variations of slotted fencing include some bracing or tieback into the streambank to increase strength.... . • Low slotted board fences. .. which do not control the entire flood flow.. Stream-forming flow Baseflow Streambed 16–42 Brush & rock fill optional . (v) Piling revetment with slotted board fencing —This type of revetment consists of slotted board fencing made of wood pilings and horizontal wood timbers (figs. • May not be appropriate where unusually hard materials are encountered in the channel bottom. Existing vegetation. Brace . . and to trap sediment.... can be very effective for streambank toe protection where the toe is the weak part of the streambank. . and vertical fence boards depend on height of fence. reduce velocity against the streambank.. . .. . • Useful in deeper stream channels with large flow depths.... . cross members. • Most effective on streams that have a heavy sediment load of sand and silt. and possible dangers for recreational uses (boating. wood pilings. swimming. Construction guidelines Inert materials—Slotted fencing is constructed of wood boards. Avoid materials that may produce toxicity effects in aquatic ecosystems. changes in flows where large amounts of debris are collected. habitat damage caused by driving or installing pilings with water jets. rafting. Increase the piling depth when penetration resistance is less than 10 blows per foot.Chapter 16 Streambank and Shoreline Protection • Should not be used without careful consideration of its long-term effects upon aesthetics. • Take great care during layout to tie in the upstream end adequately to prevent flanking and unraveling. December 1996) 16–43 . Figure 16–28 Part 650 Engineering Field Handbook Installation • See (iv) Piling revetment with wire or geotextile fencing for general construction guidelines. and woven wire. • Drive the timber piling to a depth below the channel bottom that is equal to the height of the slotted fence above the expected scour line when stream soils have a standard penetration resistance of 10 or more blows per foot. or wading). Slotted board fence system (210-vi-EFH. or steel. . and naturally revegetate as the systems.. or steel jack Not to scale Cable . swimming. 1 foot 4 feet 5 to 20 feet Baseflow Streambed Upstream anchor Downstream & inline anchor 16–44 Streambed (210-vi-EFH.. • Most effective on long. Staples 6 feet .. . Concrete jack details Front elevation Concrete. 16–29. changes in flows where large amounts of debris are collected. when functioning properly. • Somewhat flexible because of their physical configuration and installation techniques that allow them to adjust to slight changes in the channel grade.. fish habitat damage. or wading). including cable.. • Collect coarse and fine sediment. radius curves. The jacks are placed in rows parallel to the eroding streambank and function by trapping debris and sediment. rafting.. . They are often constructed in groups called jack fields (figs.Chapter 16 Streambank and Shoreline Protection (vi) Jacks or jack fields—Jacks are individual structures made of wood. debris-laden streams. and possible dangers for recreational uses (boating. • Are complex systems requiring proper design and installation for effective results. and 16–31). . Applications and effectiveness • May be an effective means of controlling bank erosion on sinuous streams carrying heavy bedloads of sand and silt during flood flows. • Not an effective alternative for redirecting flow away from the streambank. wood. • Do not use without careful analysis of its longterm effects upon aesthetics. This condition is generally indicated by the presence of extensive sandbar formations on the bed at low flow.. Figure 16–29 Part 650 Engineering Field Handbook • Do not use on high velocity.. 16–30. concrete..3/8 inch wire strands Anchor piling Cable clamps Notch .. become embedded in the streambank. . December 1996) . anchoring systems. and assembly configurations. however. Rock placed at base of jack to prevent floating.400 pounds. a sturdy construction would be to tie all ends together. 9 galvanized wire.Chapter 16 Streambank and Shoreline Protection Construction guidelines Inert materials—Jacks may be constructed of wood. or concrete. Floodplain Stream channel Cable Deadman anchor (timber log) Note: Supplemental anchors should be used to tie individual jacks into the streambank. Figure 16–30 Part 650 Engineering Field Handbook Steel jacks are used in a manner similar to that of wood jacks. Wooden jack systems dimensioned in this chapter are limited to shallow flow depths of 12 feet or less. cable size. leg assemblies. but engineering design is required to determine different attachment methods. Wooden jack field ted tec nk Ba to ro ep b Note: For streams of high velocity. Concrete beams may be substituted for steel. and anchor placement details vary. anchor blocks. (210-vi-EFH. Wooden jacks are constructed from three poles 10 to 16 feet long. Cables used to anchor the wood jack systems should be 3/8-inch diameter or larger with a minimum breaking strength of 15. They are crossed and wired together at the ends and midpoints with No. December 1996) 16–45 . steel. • Anchor the jacks in place by a cable strung through and tied to the center of the jacks with cable clamps. The first two pilings at the upstream end of the jack line should be driven no more than 12 feet apart to reduce the effect of increased water force from trash buildup. Space pilings 75 to 125 feet apart along the jack row. • Supplement the jack string or field with vegetative plantings. December 1996) . Place anchors up the streambank rather than in the streambed. This encourages a dry surface for construction and provides some additional elevation for protection from greater depths of flow. Alternatively. • Attach an anchored 3/8-inch diameter wire cable to one leg of each jack to prevent rotation and improve stability. • Consider pilings if streambed anchors are required. which should be wired onto the jack poles. each 14 feet wide. • Space jacks closely together with a maximum of one jack dimension between them to provide an almost continuous line of revetment. anchor jack rows at intermediate points along the curve to isolate damages to the jack row. Two 3/8-inch diameter wire cables tied to timber or steel pilings provide adequate anchors. Depths may vary from 5 to 20 feet and must be specified based on individual site characteristics. thereby securing all the jacks as a unit. Extend bank protection far enough to prevent flanking action. Concrete jack system several years after installation (210-vi-EFH. Wooden jacks are weighted by rocks. Dormant posts offer a compatible component in the system.Chapter 16 Streambank and Shoreline Protection Installation • Jack rows can be placed on a shelf 14 feet wide for one line and on two shelves. The cable should be tied to a buried anchor or pilings. jacks can be constructed on the streambed or on the top of the bank and moved into place. This prevents local scour. Grade the shelf to slope from 1 foot above the streambed at the side nearest the stream to 3 feet above the streambed at the side nearest the slope. Ensure the jack row is anchored to a hardpoint at the upstream end. • On long curves. Figure 16–31 16–46 Part 650 Engineering Field Handbook • Bury anchors or drive anchor pilings to the design depth determined by an engineer. for a double jack row. with closer spacing on shorter curves. • Place jack rows perpendicular to the bank at regular intervals where jack rows are not close to existing banks. . Removing streambed materials tends to destroy the diversity of physical habitat necessary for optimum fish production.... It can be designed to self-adjust to eroding foundations. ... geotextile fabric.... .... Material forming an armor layer that protects the bed from erosion should not be removed. The cost of quarrying. 16–43) can be an alternative to rock riprap under many circumstances... .. .......... concrete cellular blocks......16–32 and 16–33).Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook (vii) Rock riprap—Rock riprap.. 16–34.... and 16–42. Following disruption of the existing streamflow by alteration of the stream channel.... Gabion baskets. transporting..... Figure 16–32 Rock riprap details Cross section Not to scale Existing vegetation... • Is inert so does not depend on specific environmental or climatic conditions for success.... further damage results as the stream seeks to reestablish its original meander pattern.. Construction guidelines Inert materials—Cobbles and gravel obtained from the stream bed should not be used to armor streambanks unless the material is so abundant that its removal will not reduce habitat for benthic organisms and fish. Applications and effectiveness • Provides long-term stability.... • May be designed for high velocity flow conditions.... is an effective method of streambank protection (figs..... • Has structural flexibility. or similar systems (figs. plantings or soil bioengineering systems Erosion control fabric Stream-forming flow Top of riprap minimum thickness = maximum rock size 1 1... . . 16–35b.. Construction activities often create channels of uniform depth and width in which water velocities increase. December 1996) 16–47 . . Use of stream cobble and gravel may require permission from state and local agencies.) Baseflow Streambed Gravel bedding. .. ....5 (max. • Has a long life and seldom needs replacement.. as needed Bottom of riprap minimum thickness = 2 x maximum rock size (210-vi-EFH. not only in the project area. and placing the stone and the large quantity of stone that may be needed must be considered. but upstream and downstream as well.. properly designed and placed. 16–35a.............. Channel alignment. debris and ice impact. rock gradation.Chapter 16 Streambank and Shoreline Protection Upstream. Nearly all use either an allowable velocity or tractive stress methodology as the basis for determining a stable rock size. All four methods listed in the table provide the user with a design rock size for a given set of input parameters. Two of the more direct methods of obtaining a rock size are included in appendix 16A. the stream may seek to adjust to the new gradient by actively eroding or grading its banks and bed. Rock riprap revetment system (210-vi-EFH. Figure 16–33 16–48 Part 650 Engineering Field Handbook Numerous methods have been developed for designing rock riprap. Table 16–2 lists several accepted procedures currently used in the NRCS. angularity. The eroded material may be deposited in the channel downstream from the alteration causing additional changes in flow pattern. The first time user is advised to use more than one method in determining rock size. These forces must be considered in any analytical procedure for determining a stable rock size. Resisting the hydrodynamic effects are the force components resulting from the submerged weight of the rock and its geometry. Rock riprap on streambanks is affected by the hydrodynamic drag and lift forces created by the velocity of flow past the rock. December 1996) . surface roughness. The downstream channel will then also adjust to the new gradient and increased streamflow velocity by scour and bank erosion or further deposition. Availability of rock and experience of the designer continue to play important roles in determining the appropriate size rock for any given job. The table provides summary information and references where appropriate. and placement are other factors that must be considered when designing for given site conditions. FWS-Lane Appendix 16A (reprint from SCS Engineering Design Standards—Far West States. chapter 16. The bank soils. EM 1110-2-1601. The basic stone weight is often doubled to account for debris. where subject to wave action. or where flow velocity exceeds 10 feet per second. • Prevents movement and loss of fine grained soil into the large void spaces of the riprap. Figure 16A–3 in appendix 16A can help determine rock gradation limits for any calculated basic rock size (D50. Tractive stress— Monograph developed from Lane's work. Federal Highway Administration Hydraulic Engineering Circular No. Hydraulic Design of Flood Control Channels. Enter monograph with channel hydraulic and physical data to solve for basic rock size (D75). and so forth). Tractive Force Theory— Uses velocity as a primary design parameter. 1969). bank seepage. The void space between rocks in riprap is generally many times greater than the void space in existing bank materials. Design of Riprap Revetment (1989). Generally results in a conservative rock size.Chapter 16 Streambank and Shoreline Protection A well graded rock provides the greatest assurance of stability and long-term protection. Bedding material is generally a pit run sand-gravel mixture. forces acting on the bedding result only from the action of flow past or over the rock riprap. and rock gradation and thickness are factors to consider when determining the transition material. Bedding is suitable for those sites where bank materials are plastic and forces can be considered external. Allowable velocity— Basic equation developed by COE from study of models and comparison to field data. Allowable velocity— Curve developed from Isbash work. Methods for rock riprap protection Method (reference) Basis for rock size Procedure Comments Isbash Curve Appendix 16A (reprint from SCS Engineering Field Manual. (210-vi-EFH. Detailed procedure can be used on natural or prismatic channels. Use judgment to factor in site conditions. Stability factor requires user judgment of site conditions. Satisfactory gradation limits and thickness of the rock riprap can be determined from the basic stone size. A transition zone serves two purposes: • Distributes the weight of rock to the underlying soil. December 1996) 16–49 . 11. COE Method Corps of Engineers. bedding. D75. Table 16–2 Part 650 Engineering Field Handbook The transition zone can be designed as a filter. Bedding is not recommended for conditions where flow occurs through the rock (as on steep slopes). 7/91. or geotextile. Easy to use procedure. Use equation with known site data and user determined stability factor to solve for basic rock size (D50). Use equation or graphs and site physical and hydraulic data to determine basic rock size (D30). that is. Use design velocity and curve to determine basic rock size (D100). 1970). Poorly graded rock results in weak areas where individual stones are subject to movement and subsequent revetment failure. Nonwoven geotextiles are widely used as a substitute for bedding and filter material. Installation • Minimum thickness of the riprap should at least equal the maximum rock size at the top of the revetment. and ease of placement are contributing factors.. . part 633 of the NRCS National Engineering Handbook. seepage forces exist. and similar systems. Construction and Construction Materials. The filter or bedding material should be at least 6 inches thick. the rock must be dumped in a manner that will not separate small and large stones or cause damage to the filter fabrics. . The thickness is often increased at the base of the revetment to two or more times the maximum rock size. • The toe for rock riprap must be firmly established. Availability. The finished surface should not have pockets of finer materials that would flush out and weaken the revetment. Chapter 17. . January 1994. • A filter or bedding must be placed between the riprap and the bank except in those cases where the material in the bank to be protected is determined to be a suitable bedding or filter material. December 1996) 18 in min. For guidance in selection of the proper geotextile. . In critical applications or where experience indicates problems with the loss of bank material under riprap. The site should be evaluated for potential seepage pressures from existing or seasonal water table. Their recommendations are good references in use of gabions. cellular blocks. A filter is recommended where bank materials are nonplastic. The riprap should extend up the bank to an elevation at which vegetation will provide adequate protection. However.Chapter 16 Part 650 Engineering Field Handbook Streambank and Shoreline Protection A filter is a graded granular material designed to prevent movement of the bank soil.. Stream-forming flow Baseflow Geotextile fabric Streambed Cross section Not to scale 16–50 (210-vi-EFH. if ever. A 3-inch layer of bedding material over the geotextile prevents this movement. or other factors. The Engineering Field Handbook.5:1. it is adequate to dump the rock and rearrange it with a minimum of hand labor. .. .. • Hand-placing all rock in a revetment should seldom. This is important where the stream bottom is unstable or subject to scour during flood flows. Manufacturers have developed design recommendations for various flow and soil conditions. cost. Figure 16–34 Concrete cellular block details Revegetate 6 in above design wave height or top of slope Steepest slope of block placement 3:1 12 in min. This slope should not be steeper than 1. or where bedding is not adequate protection for the external forces as noted above. Sufficient hand placing and chinking should be done to provide a well-keyed surface. While the revetment may have a somewhat less finished look.. Geotextile that can move with changes in seepage pressure or external forces permits soil particle movement and can result in plugging of the geotextile. Guide to Use of Geotextile. surface runoff. rapid fluctuations in streamflow (rapid drawdown).. has additional information on riprap construction and materials. be necessary. The geotextile material must maintain intimate contact with the subsurface. refer to NRCS Design Note 24. use chapter 26. for guidance in designing granular filters. • A nonwoven geotextile may be used in lieu of a bedding or filter layer under the rock riprap. • Banks on which riprap is to be placed should be sloped so that the pressure of the stone is mainly against the bank rather than against the stone in the lower courses and toe. ... December 1996) Part 650 Engineering Field Handbook 16–51 .Chapter 16 Streambank and Shoreline Protection Figure 16–35a Concrete cellular block system before backfilling Figure 16–35b Concrete cellular block system several years after installation (210-vi-EFH. Applications and effectiveness • Protect slopes from shallow slides or undermining while trapping sediment that encourages plant growth within the fiber roll..... • Place the coconut fiber roll in the trench. product can mold to existing curvature of streambank.... • Manufacturers estimate the product has an effective life of 6 to 10 years. . • Produce a well-reinforced streambank without much site disturbance. Figure 16–36 Coconut fiber roll details Cross section Not to scale Existing vegetation... • Flexible.. Part 650 Engineering Field Handbook • Prefabricated materials can be expensive.. .. . plantings or soil bioengineering systems Herbaceous plugs Erosion control fabric Stream-forming flow Baseflow Coconut fiber roll Streambed 2 in... 16–36. Construction guidelines • Excavate a shallow trench at the toe of the slope to a depth slightly below channel grade.Chapter 16 Streambank and Shoreline Protection (viii) Coconut fiber rolls—Coconut fiber rolls are cylindrical structures composed of coconut husk fibers bound together with twine woven from coconut (figs. 16–37a. This material is most commonly manufactured in 12-inch diameters and lengths of 20 feet. • Drive 2 inch x 2 inch x 36 inch stakes between the binding twine and coconut fiber.... generally at the stream-forming flow stage... . . Stakes should be placed on both sides of the roll on 2 to 4 feet centers depending upon anticipated velocities. notch outside of stakes on either side of fiber roll and secure with 16-gauge wire.. . and 16–37b). by 2 in. by 36 in.. December 1996) ... Tops of stakes should not extend above the top of the fiber roll.... • In areas that experience ice or wave action. It is staked in place at the toe of the slope. oak stakes 16–52 (210-vi-EFH. Chapter 16 Streambank and Shoreline Protection Figure 16–37a Coconut fiber roll Figure 16–37b Coconut fiber roll system (210-vi-EFH. December 1996) Part 650 Engineering Field Handbook 16–53 . other materials are used including timber. • Construct jetties with a level top or a downward slope to the outer end (riverward). jetties change the direction of flow by obstructing and redirecting the streamflow. or other qualified discipline with knowledge of open channel hydraulics should be consulted for specific considerations and guidelines. concrete. • Space jetties to account for such characteristics as stream width. however. engineer. rooted herbaceous plants may be installed in the coconut fiber. (210-vi-EFH. Applications and effectiveness • Used successfully in a wide variety of applications in all types of rivers and streams.Chapter 16 Streambank and Shoreline Protection • Backfill soil behind the fiber roll. Rock jetties typically have 2:1 side slopes with an 8 to 12-foot top width and 2:1 end slope. downstream. • May develop scour holes just downstream and off the end of the jetties. The length varies but should not unduly constrict the channel. Perpendicular and downstream orientation are the most common. • Can be augmented with vegetation or soil bioengineering systems in some situations. 16–54 Part 650 Engineering Field Handbook Construction guidelines Inert materials—Rock filled jetties are the most common. (ix) Stream jetties—Jetties are short dike-like structures that project from a streambank into a stream channel. and rock protected earth. deposited material upstream of jetties. • Orient jetties either perpendicular to the streambank or angled upstream or downstream. and radius of curvature. Their design and construction require specialized skills.e. Installation • Use a D50 size rock equal to 1. A fluvial geomorphologist. • If conditions permit. • Size and space jetties so that flow passing around and downstream from the outer end will intersect the next jetty before intersecting the eroding bank. December 1996) . i. The base of the jetty should be keyed into the bed a minimum depth equal to the D100 rock size. • Install appropriate vegetation or soil bioengineering systems upslope from fiber roll. or perpendicular to the bank (figs. In function and design. Place rock a short distance on either side of the jetty along the bank to prevent erosion at this critical location. Jetties deflect or maintain the direction of flow through and beyond the reach of stream being protected. Typical spacing is 2 to 5 times the jetty length. gabions. • Can be complex and expensive. 16–38 and 16–39)..5 to 2 times the d50 size determined from rock riprap design methods for bank full flow condition. • Tie jetties securely back into the bank and bed to prevent washout along the bank and undercutting. stream velocity. The top of the jetty at the bank should be equal to the bank height. Most are constructed to the top of the bank and can be oriented either upstream. They may consist of one or more structures placed at intervals along the bank to be protected. • Effective in controlling erosion on bends in river and stream systems. approx..... top width ..... D100 1: (210-vi-EFH.....Chapter 16 Part 650 Engineering Field Handbook Streambank and Shoreline Protection Figure 16–38 Stream jetty details Cross section Not to scale .. .. Length of jetty (varies) Stream-forming flow Existing bank 2:1 Baseflow Streambed Rock riprap Front elevation Not to scale 1 1: 8-12 feet... .. 2:1 2:1 1 1:1 Key into streambed. December 1996) 16–55 . Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Figure 16–39a Stream jetty placed to protect railroad bridge Figure 16–39b Long-established vegetated stream jetty. with deposition in foreground 16–56 (210-vi-EFH. December 1996) . • Require less rock and stream disturbance than jetties.Chapter 16 Streambank and Shoreline Protection (x) Stream barbs—Stream barbs are low rock sills projecting out from a streambank and across the stream's thalweg to redirect streamflow away from an eroding bank (figs. Part 650 Engineering Field Handbook Installation • Use a D50 size rock equal to two times the d50 size determined from rock riprap design methods for bank full flow condition. The specific spacing is dependent on finding the point at which the streamflow leaving the barb intersects with the bank.5 to 2 times the D50 size. December 1996) 16–57 . • Effective in control of bank erosion on small streams. at a minimum. • Key the barb into the stream bed to a depth approximately D100 below the bed.75D50. but not less than a typical construction equipment width of 8 to 10 feet. the barb is long enough to cross the stream flow low thalweg. (210-vi-EFH. • Improve fish habitat (especially when vegetated). • Align the barb so that the flow off the barb is directed toward the center of the stream or away from the bank.16–40 and 16–41). The minimum rock size should not be less than . Stream barbs are always oriented upstream. • Construct the barb above the streambed to a height approximately equal to the D100 rock. • Space the barbs apart from 4 to 5 times the barb’s length. Construction of barbs can begin at the streambank and proceed streamward using the barb to support construction equipment. Application and effectiveness • Used in limited applications and range of applicability is unclear. • Ensure that. but generally not over 2 feet. The maximum rock size (D100) should be about 1. The acute angle between the barb and the upstream bank typically ranges from 50 to 80 degrees. • Can be combined with soil bioengineering practices. • Can be complex and expensive. The width should be at least equal to 3 times D100. Flow passing over the barb is redirected so that the flow leaving the barb is perpendicular to the barb centerline. Construction guidelines Inert materials—Stream barbs require the use of large rock. . Length determined by design (L) Stream-forming flow Slope Baseflow Geotextile fabric Streambed Key into streambed approx... ... (L) C 50° to 80° C of stream barb Vegetative bank between barbs Flow Cross section .Chapter 16 Figure 16–40 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Stream barb details Plan view Not to scale 8 ft min..... . min.. December 1996) .. . D100 16–58 (210-vi-EFH. Not to scale Existing grade 8 ft..... December 1996) 16–59 .Chapter 16 Figure 16–41 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Stream barb system (210-vi-EFH. 5 inches in diameter and must be long enough to reach beyond the back of the rock basket structure into the backfill or undisturbed bank. (210-vi-EFH. and then folded shut and wired at the ends and sides. Should be constructed to a maximum of 5 feet in overall height. • Gabions used as mattresses should be a minimum of 9 inches thick for stream velocities of up to 9 feet per second. The live cuttings must extend beyond the backs of the wire baskets into the fill material. Install geotextiles so that they lie smoothly on the prepared foundation. and fill the gabions with rock. lateral earth stresses. • Place bedding or filter material in a uniformly graded surface. • Where gabions are designed as a structural unit. • Can be fabricated on top of the bank and then placed as a unit. Increase the thickness to a minimum of 1. • Lower initial cost than a concrete structure. Wire Gabions. Compaction of materials is not usually required. • Not designed for or intended to resist large. • Can be placed as a continuous mattress for slope protection. Avoid use where streambed material might abrade and cause rapid failure of gabion wire mesh. place live branch cuttings on the wire baskets perpendicular to the slope with the growing tips oriented away from the slope and extending slightly beyond the gabions. • Assemble. provides detailed information on their installation. branches should range from 0. These gabions take root inside the gabion baskets and in the soil behind the structures. Be certain that all stiffeners and fasteners are properly secured.5 to 2. Applications and effectiveness • Useful when rock riprap design requires a rock size greater than what is locally available.Chapter 16 Streambank and Shoreline Protection (xi) Rock gabions—Rock gabions begin as rectangular containers fabricated from a triple twisted. and sliding must be analyzed in a manner similar to that for gravity type structures. • Place the gabions so that the vertical joints are staggered between the gabions of adjacent rows and layers by at least one-half of a cell length. Slopes steeper than 2:1 should be analyzed for slope stability. • Excavate the back of the stable foundation (closest to the slope) slightly deeper than the front to add stability to the structure. • Repeat the construction sequence until the structure reaches the required height. • Have a short service life where installed in streams that have a high bed load. Gabions can be coated with polyvinyl chloride to improve their service life where subject to aggressive water or soil conditions. filled with stones. • Tolerate limited foundation movement. hexagonal mesh of heavily galvanized steel wire. • Place backfill between and behind the wire baskets. 16–60 Part 650 Engineering Field Handbook Construction guidelines Live material sizes—When constructing vegetated rock gabions. December 1996) . In time the roots consolidate the structure and bind it to the slope. wired to adjoining gabions.5 feet for velocities of 10 to 14 feet per second. overturning. place. Installation • Remove loose material from the foundation area and cut or fill with compacted material to provide a uniform foundation. • Effective where the bank slope is steep (typically greater than 1. NRCS Construction Specification 64. including the excavation required for a stable foundation. below water if necessary. Inert materials—Galvanized woven wire mesh or galvanized welded wire mesh baskets or mattresses may be used. Empty gabions are placed in position. Vegetation can be incorporated into rock gabions. The baskets or mattresses are filled with sound durable rock that has a minimum size of 4 inches and a maximum of 9 inches. This provides additional stability to the structure and ensures that the living branches root well for vegetated rock gabions. • Appropriate at the base of a slope where a low wall may be required to stabilize the toe of the slope and reduce its steepness. if desired. by placing live branches on each consecutive layer between the rock-filled baskets (fig. • For vegetated rock gabions. Place soil over the cuttings and compact it. • Useful where space is limited and a more vertical structure is required. the effects of uplift. 16–42 and 16–43).5:1) and requires structural support. .... A 3-inch layer of sand-gravel between the gabions and the filter material assures that contact is maintained.. a tieback into the bank and bed should be provided to protect the revetment from undermining or scour...... ..to 1-inch diameter) Erosion control fabric Stream-forming flow Geotextile fabric Baseflow Gabion baskets Streambed 2 to 3 feet Note: Rooted/leafed condition of the living plant material is not representative of the time of installation.. Geosynthetics can be used in lieu of granular filters for many applications.. plantings or soil bioengineering systems Cross section Not to scale Compacted fill material Live branch cuttings (1/2..... . Figure 16–42 Vegetated rock gabion details Existing vegetation................ The concrete for the cap should be placed after initial settlement has occurred. . .. when drainage is critical. A concrete cap 6 inches thick with 3 inches penetration into the basket is usually sufficient.Chapter 16 Part 650 Engineering Field Handbook Streambank and Shoreline Protection • Where abrasive bedloads or debris can snag or tear the gabion wire. a concrete cap should be used to protect those surfaces subject to attack. however. . (210-vi-EFH. .... .. • At the toe and up and downstream ends of gabion revetments... .. • A filter is nearly always needed between the gabions and the foundation or backfill to prevent soil movement through the baskets.... . . ... the fabric must maintain intimate contact with the foundation soils. ...... December 1996) 16–61 . Schiechtl photo) (210-vi-EFH.Chapter 16 Figure 16–43 16–62 Streambank and Shoreline Protection Vegetated rock gabion system (H. December 1996) Part 650 Engineering Field Handbook .M. Methods for computing wave height using fetch length are in NRCS Technical Releases 56 and 69. The slope below waterline should be representative of the slope for a distance of at least 50 feet. • Potential wave parameters. This major turbulence stirs up material from the shore bottom or erodes it from banks and bluffs. dissipating energy. For the scope of this chapter. under the influence of waves and currents should be addressed in groin design. the total height of the wave is three times that visible) and the decreased wave action caused by shallow water. This information is used to locate structures properly with respect to adjacent properties and so that groins can fill most quickly and effectively. It is important to determine that the supply of transport material is not coming from the bank being protected and the predominant direction of littoral transport. soil bioengineering. records of lake levels. They consist of vegetation. This eventually causes it to break or collapse.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook (b) Design considerations for shoreline protection 650. Effective fetch length also needs to be considered in determining wave height. (2) Offshore depth and wave height Offshore depth is a critical factor in designing shoreline protection measures. (2) Planning for shoreline protection measures The following items need to be considered for shoreline protection in addition to the items listed earlier in this chapter for planning streambank protection measures: • Mean high and low water levels or tides. No simple ways to measure the supply are available.1602 Shoreline protection (1) Beach slope Slopes should be determined above and below the waterline. or in water that may become deep. • Slope configuration above and below waterline. The rate of littoral transport and the supply are as important as the direction of movement. floating ice. • Evidence of littoral drift and transport. • Maintenance requirements. • Causes of erosion. supply may be determined by observation of existing structures. (3) Water surface The design water surface is the mean high tide or. or from topographic maps of the reservoir site in conjunction with observed high and normal water lines along the shore. structures. or a combination of these. it begins to drag on the bottom. • Adjacent land use. and the presence of sandbars offshore. As a wave moves toward shore. and surface runoff from adjacent uplands may also cause shorelines to erode. are beyond the scope of this chapter. sand beaches. Fluctuating tides. (a) General Shoreline erosion results primarily from erosive forces in the form of waves generally perpendicular to the shoreline. Another factor to be considered is that littoral transport often reverses directions with a change in season. in nontidal areas. Other important considerations are the dynamic wave height acting in deep water (roughly. freezing and thawing. the mean high water. Other (210-vi-EFH. auger samples of the sand above the parent material on the beach. December 1996) 16–63 . (1) Types of shoreline protection Systems for shoreline protection can be living or nonliving. • Nature of the soil material above and below water level. (4) Littoral transport The material being moved parallel to the shoreline in the littoral zone. Structures that must be constructed in deep water. This information may be obtained from tidal tables. If the use of riprap is being considered on a highly erodible foundation. such as sand. They generally are constructed in groups called groin fields. (7) Adjacent shoreline and structures Structures that might have an effect on adjacent shoreline or other structures must be examined carefully. 16–44 and 16–45). shoreline configuration. A thin sand lens can result in erosion problems since it may be washed out when subjected to high tides or wave action for extended periods of time. causing it to break away. A very dense.Chapter 16 Streambank and Shoreline Protection considerations are existing barriers. if the littoral transport is clay or silt rather than sand. End sections need to be adequately anchored to existing measures or terminated in stable areas. bulkheads. A soft foundation. heavy clay can offer more resistance to wave action than noncohesive materials. The resulting void will no longer support the bank above it. and their primary purpose is to trap littoral drift. For example. Groins are most effective in trapping sand when littoral drift is transported in a single direction. such as dredge spoil. and groins no higher than 3 feet above mean high water. The entrapped sand between the groins acts as a buffer between the incoming waves and shoreline by causing the waves to break on the newly deposited sand and expend most of their energy there (figs. • Will not fill until all preceding updrift groins have been filled. as well as soil bioengineering and other vegetative systems used alone or in combination with structural measures. 16–64 Part 650 Engineering Field Handbook (c) Protective measures for shorelines The analysis and design of shoreline protection measures are often complex and require special expertise. (6) Foundation material The type of existing foundation may govern the type of protection selected. may result in excessive flotation or movement of the structure in any direction. For this reason the following discussion is limited to revetments. (210-vi-EFH. a filter will be needed to prevent fine material from washing through the voids. The net direction of transport is an important and complex consideration. and inlets that tend to push the supply offshore and away from the area in question. Existing vegetation should be saved as an integral part of the erosion control system being installed. a rock bottom will not permit the use of sheet piling. (8) Existing vegetation The installation of erosion control structures can have a detrimental effect upon existing vegetation unless steps are taken to prevent what is often avoidable site disturbance. Construction guidelines Inert materials—The most common type of structural groin is built of preservative-treated tongue and groove sheet piling. December 1996) . especially estuarine wetlands. (5) Bank soil type Determining the nature of bank soil material aids in estimating the rate of erosion. • Filling the groin field with borrowed sand may be necessary. Consideration must be given to the possible effects that erosion control measures can have on adjacent areas. (1) Groins Groins are somewhat permeable to impermeable finger-like structures that are installed perpendicular to the shore. Applications and effectiveness • Particularly dependent on site conditions. or key to bulkhead Sheet piling Ground surface 3 1/2 ft min..Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook .. or 2 in.. treated T&G sheet piling 6 in..spacing varies Mean high water elevation 24 in. Cross section 2 by 8 stringers 24 in.. by 10 in. polepiles Varies Plan (210-vi-EFH.. Figure 16–44 Timber groin details Top of bank 6-inch diameter poles . by 8 in.... . .... December 1996) 16–65 ....... min. STD placement of galvanized 20d nails Bank Mean high water elevation 2 in.... • Install the second group of groins after the first has filled and the material passing around or over the groins has again stabilized the downdrift shoreline. This provides the means to verify or adjust the design spacing. the groins are usually shorter. Decrease the height seaward at a gradual rate to mean high water elevation. Timber groin system (210-vi-EFH.Chapter 16 Streambank and Shoreline Protection Installation • Groins must extend far enough into the water to retain desired amounts of sand. • Measure the groin height on the shoreline so that it will generally be at high tide or mean high water elevation plus 2 or 3 feet for wave surge height. • Groins are particularly vulnerable to storm damage before they fill. When used in conjunction with bulkheads. The distance between groins generally ranges from one to three times the length of the groin. so initially only the first three or four at the downdrift end of the system should be constructed. Figure 16–45 16–66 Part 650 Engineering Field Handbook • Key the shoreward end of the groins into the shoreline bank for at least 2 feet or extend them to a bulkhead. December 1996) . and face boards must be engineered on a site-by-site basis. • Thickness and spacing of pilings. • Scour at the base of the bulkhead also causes failure. or jetted depending on the foundation materials. Applications and effectiveness • Generally constructed where wave action will not cause excessive overtopping of the structure. cross member. Depth of piling must be at least equal to the exposed height below the point of maximum anticipated scour. which causes bank erosion to continue as though the bulkhead were not there. 16–46 and 16–47). • Place stones or other appropriate materials at the base of the bulkhead to absorb wave energy. The vertical face of the bulkhead redirects wave action to cause excessive scour at the toe of the structure unless it is protected. • Pilings can be drilled. or aluminum sheet piling installed parallel to the shoreline. December 1996) 16–67 . Part 650 Engineering Field Handbook Installation • Use environmentally compatible treated timber. Figure 16–46 Timber bulkhead system (210-vi-EFH.Chapter 16 Streambank and Shoreline Protection (3) Bulkheads Bulkheads are vertical structures of timber. Construction guidelines Inert materials—The most common materials used for bulkhead construction are timber (figs. and masonry. concrete (figs. 16–48 and 16–49). supports. driven. • In salt water environments. steel. use noncorrosive materials to the greatest extent possible. concrete. ..Chapter 16 Part 650 Engineering Field Handbook Streambank and Shoreline Protection .. Figure 16–47 Timber bulkhead details Cross section Existing vegetation. . ...C... . . . ... plantings or soil bioengineering systems Not to scale Backfill and slope to meet site conditions Erosion control fabric 2 in x 6 in cap 7/16 galvanized bolt 2 in x 8 in x 16 in wale 3 ft Mean high water elevation Existing bank 6 in x 6 ft anchor pile 5 ft min. plantings or soil bioengineering systems Cross section Berm . . 10' O. . .. . .. ... .... 2 x wave height Backfill and slope to meet site conditions Mean high water elevation Max... ..... Geotextile fabric 3/8 in cable 2 in x 8 in x 16 in wale 5 ft Note: Locate bottom wale near ground line. Not to scale Erosion control fabric 3:1 or flatter Gravel drain Geotextile fabric Weep holes 11/2 dia.. ...... . December 1996) . ... not more than 3 inches on center from top wale. 7 ft 2 in x 8 in or 2 in x 10 in T&G sheet piling 6 in x 10 in fender pile Existing vegetation. Wave height or 18" (whichever is least) 2 x H or 2 x wave height (whichever is greater) 16–68 (210-vi-EFH.min. . .. .... . ... ....... . .... 4 feet Coarse gravel or riprap (as needed) . ..-8 in.c.. dia. .. 1 ft. or joint reinforcement at 8 in o.c. . 4 bars in bond beams at 16 in. min. . . 4 bars at 12 in... 1 ft.-3 in 1 ft. 4 bars at 12 in.-6 in. . . 4 ft. .. at 10 ft.. .. ... 2 x wave height 8 in. 4 bars at 12 in. (210-vi-EFH. Weep holes 1.. 4 ft. . at 10 ft.... 4 bars at 16 in. .-1 in... o. ... o. 4 bars at 16 in.5 in. No. ... No. dia. . 4 bars at 16 in.. December 1996) 16–69 . whichever is least 10 in. Coarse gravel or riprap as needed Wave height or 18 in.Chapter 16 Figure 16–48 Streambank and Shoreline Protection Part 650 Engineering Field Handbook .c. water elevation Horizontal joint reinforcement 2 . o.c.. . o.c. plantings or soil bioengineering systems Berm . o. min. 14 in.. Wave height or 18 in. No.. . 8 in.. .c...c. . Cross section Concrete block wall Existing vegetation. 4 bars at 16 in. ... ....-2 in 2 ft.. No. . 3 ft..no.. o. .. Not to scale Erosion control fabric 3:1 or flatter Gravel drain Geotextile fabric No. (whichever is least) No. Backfill and slope to meet site conditions Mean high Max.min. .... Not to scale Backfill and slope to meet site conditions Erosion control fabric 3:1 or flatter Gravel drain No.c. . o. o.. 2 x wave height 8 in. Max. . o.. . Mean high water elevation Geotextile fabric Coarse gravel or riprap as needed Weep holes 1. 6 in. . Concrete bulkhead details Cross section Poured in place concrete wall Existing vegetation.min.5 in..c.c. plantings or soil bioengineering systems Berm . . 8 in. ....-2 in... . . .c... o. . 4 ft. 6 in. Chapter 16 Figure 16–49 16–70 Streambank and Shoreline Protection Concrete bulkhead system (210-vi-EFH. December 1996) Part 650 Engineering Field Handbook . December 1996) 16–71 . Concrete revetment (poured in place) (210-vi-EFH. • Subject to scour at the toe and flanking. • Preferred to bulkheads where the possibility of extreme wave action exists.Chapter 16 Streambank and Shoreline Protection (4) Revetments Revetments are protective structures of rock. Rock Riprap for Slope Protection Against Wave Action. increase the layer thickness by a factor of 1. • Angular stone is preferred for revetments.5. Applications and effectiveness • Flexible and not impaired by slight movement caused by settlement or other adjustments. thickness. 16–50 and 16–51). • If geotextile is used in place of granular filter. provides guidance for size. • Complex and expensive. NRCS Technical Release 69. • Local damage or loss of rock easily repaired. and gradation. • No special equipment required for construction. • Use a minimum thickness of 6-inch filter material under rock. Figure 16–50 Part 650 Engineering Field Handbook Construction guidelines • The size and thickness of rock revetments must be determined to resist wave action. or other material installed to fit the slope and shape of the shoreline (figs. If rounded stone is used. concrete. • The base of the revetment must be founded below the scour depth or placed on nonerosive material. thus filters are important and should always be considered. cellular blocks. cover the geotextile with a minimum of 3inches of sand-gravel before placement of rock. Chapter 16 Figure 16–51 16–72 Streambank and Shoreline Protection Rock riprap revetment (210-vi-EFH. December 1996) Part 650 Engineering Field Handbook . live siltation. slight undercutting in spots with an occasional slide on the bank. The problems are often caused by boat wake or excessive upland runoff. disturbed areas should be revegetated with native trees. NRCS Technical Release 56. (7) Soil bioengineering systems Soil bioengineering systems that are best suited to reducing erosion along shorelines are live stakes. Consult local technical guides and plant material specialists for appropriate plant species and planting specifications. Determine if the vegetation disappeared because of a single. installations may be enhanced with a layer of long straw mulch covered with jute mesh or. such as those manufactured from coconut husks. infrequent storm. December 1996) 16–73 . Natural geotextiles. in more critical areas. Natural geotextile with long straw for higher energy shorelines. and work well to protect the ground. To reduce failure until root establishment occurs. • Spread long straw on the slope above the trench to the approximate location of the next trench to be constructed upslope. once the saturated condition is remedied. or if plants are being shaded out by developing overstory trees and shrubs. • Pull the fabric upslope over the long straw and spread in the next excavated trench. the shoreline problem may be solved with more vegetation. a natural geotextile fabric. live fascines. • Spread jute mesh or geotextile fabric across the excavated trench and temporarily leave the remainder on the slope immediately above the trench. (6) Patching A shoreline problem is often isolated and requires only a simple patch repair. reed clumps. with the following variations: • Excavate a trench approximately 10 inches wide and deep.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook (5) Vegetative measures If some vegetation exists on the shoreline. Slides that occur because of a saturated soil condition are best alleviated by providing subsurface drainage or a diversion. Inert materials—Dead stout stakes approximately 3 feet long to anchor well in loose sand. Fill undercut areas with stone sandbags or grout-filled bags and repair with a grass transplant. Trenches should be spaced 3 to 5 feet apart and parallel to each other. Jute mesh with long straw for low energy shorelines. are strong. durable. and fairly good vegetative growth on the shoreline. Installation The installation methods are similar to those discussed for live fascines. however. beginning at one end of and parallel to the shoreline section to be repaired and extending to the other end. and reed clump constructions. provides additional guidance. but over time they provide excellent soil reinforcement. brushmattresses. and forbs to establish cover. or vegetated riprap. Leaning or slipping trees in the immediate slide area may need to be removed initially because of their weight and the forces they exert on the soil. shrubs. • Place a live fascine bundle in the trench on top of the fabric and anchor with live and dead stout stakes. Refer to streambank protection section of this chapter for appropriate applications and construction guidelines. (i) Live stake—Live stakes offer no stability until they root into the shoreline area. (ii) Live fascine—The live fascines previously described in this chapter work best in shoreline applications where the ground between them is also protected. Vegetative Control of Wave Action on Earth Dams. (210-vi-EFH. Fabricate live fascine bundles approximately 8 inches in diameter. vegetated geogrid. Construction guidelines Live materials—Live cuttings as previously described for fabrication of live fascine bundles. Live stakes should be about 3 feet long. grasses. In either case revegetation is a viable alternative. • Repeat the process until the system is in place over the treatment area. branchpacking. Site characteristics that would indicate a patch solution may be appropriate include good overall protection from wave action. strong roots develop and adding resistance to sliding and shear displacement. Installation • After the trench at the bottom has been dug and the mattress branches placed. with one vertical side and the other angled toward the shoreline. 16–52 and 16–53). 16–74 (210-vi-EFH. Ideally live siltation systems are approximately perpendicular to the prevailing winds. A few dead stout stakes may be used in the mattress branch and partly wired down before covering the fabric. • At this point. Construction guidelines Live material—Live branch cuttings 0. the trench should be lined with geotextile fabric. press down the mattress brush. Applications and effectiveness • May be effective in lake areas that have fluctuating water levels since they are able to protect the shoreline and continue to grow. Applications and effectiveness Live siltation systems provide immediate erosion control and earth reinforcement functions. This helps in the final steps of covering and securing the brush and the fabric. Therefore. install the live and dead stout stakes to hold the brush in place. and place the fabric on top of the brush. chapter 18 for a more complete discussion of a brushlayer). • Reinforcing the soil as deep. Live siltation branches that have been installed in the trenches serve as tensile inclusions or reinforcing units. • Promoting seed germination for natural colonization. • Trapping debris. December 1996) . depending upon shoreline conditions and stability required. The branch tips should slope upwards at 45 to 60 degrees. • Parallel live siltation rows should vary from 5 to 10 feet apart. healthy shoreline vegetation. Steep. • Secure the live fascine. The part of the brush that protrudes from the ground assists in retarding runoff and surface erosion from wave action and wind (figs. • Drying excessively wet sites through transpiration. excavate a trench 2 to 3 feet deep and 1 to 2 feet wide. Installation is similar to brushlayering (see Engineering Field Handbook. unstable and high energy sites require closer spacing.Chapter 16 Streambank and Shoreline Protection (iii) Brushmattress—Brushmattresses for shorelines perform a similar function as those for streambanks. Part 650 Engineering Field Handbook (iv) Live siltation construction—Live siltation construction is similar to brushlayering except that the orientation of the branches are more vertical. including: • Providing surface stability for the planting or establishment of vegetation. seed. Installation • Beginning at the toe of the shoreline bank to be treated. • Reducing wind erosion and surface particle movement.5 to 1 inch in diameter and 4 to 5 feet long with side branches intact. effectiveness and construction guidelines are similar to those given earlier in this chapter. • Able to filter incoming water because they also establish a dense. • Reinforcing the soil with unrooted branch cuttings. with the following additions. and vegetation at the shoreline. .. . December 1996) 16–75 ... . . .Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Live siltation construction details Figure 16–52 Plan Not to scale Littoral transport Shoreline A Toe of shoreline bank A Live siltation constructions 5 to 10 ft Section A-A . ... (210-vi-EFH.. .. Littoral transport Live brush Excavated trench 2 to 3 ft Fill material 1 to 2 ft Live siltation branches Note: Rooted/leafed condition of the living plant material is not respresentative of the time of installation..... . December 1996) Part 650 Engineering Field Handbook . Sotir & Associates photo) (210-vi-EFH.Chapter 16 Figure 16–53 16–76 Streambank and Shoreline Protection Live siltation construction system (Robbin B. • Useful on shore sites where rapid repair of spot damage is required. Applications and effectiveness • Reduces toe erosion and creates a dense energydissipating reed bank area. Complete the installation by spreading previously excavated soil around the exposed reed clumps to cover this staked fabric. (210-vi-EFH. and compact. • Grows in water and survives fluctuating water levels.Chapter 16 Streambank and Shoreline Protection (v) Reed clump—Reed clump installations consist of root divisions wrapped in natural geotextile fabric. cattail. These clumps can be fabricated several days before installation if they are kept moist and shaded. Construction guidelines Live materials—The reed clumps should be 4 to 8 inches in diameter and taken from healthy waterdependent species. With the growing tips pointing up. such as arrowhead. or water iris. • Wrap the fabric from both sides to overlap the top. place it in the excavated trench. Wrap geotextile fabric from each side to overlap at the top and leave the reed clumps exposed before securing with dead stout stakes spaced between the clumps. Next. Wrap reed clumps in natural geotextile fabric and bind together with twine.to 3-foot-wide strip of geotextile fabric before spreading a 1-inch layer of highly organic topsoil over it at the bottom of the trench. • Reduces a long beach wash into a series of shorter sections capable of retaining surface soils. The resulting root mat reinforces soil particles and extracts excess moisture through transpiration. • Repeat the above procedure by excavating additional parallel trenches spaced 3 to 6 feet apart toward the shoreline. and backfill as described above. Place the reed clumps from one row to the next to produce a staggered spacing pattern. • To use the prefabricated reed clump roll. excavate a trench 2 inches wider and deeper than the size of the prefabricated reed roll or reed clumps. • Beginning at and parallel to the water's edge. • Offers relatively inexpensive and immediate protection from erosion. leaving the reed clumps exposed and bound with twine between each plant. December 1996) 16–77 . center the reed clumps on 12inch spacing in the bottom of the trench.to 3-footwide strip of geotextile fabric to fabricate the rolls. • To place reed clumps directly into trenches. placed in trenches.to 3. twine. • Retains soil and transported sediment at the shoreline. They may be selectively harvested from existing natural sites or purchased from a nursery. • Enhances conditions for natural colonization and establishment of vegetation from the surrounding plant community. and staked down. Inert materials—Natural geotextile fabric. Part 650 Engineering Field Handbook Installation • Reed root clumps are either placed directly into fabric-lined trenches or prefabricated into rolls 5 to 30 feet long. and 3. secure it with dead stout stakes. space clumps every 12 inches on a 2. Reed clump systems are typically installed at the water's edge or on shelves in the littoral zone (fig. The growing buds should all be oriented in the same upright direction for correct placement into the trench. first line the trench with a 2. Fill the remainder of the trench between and around reed clumps with highly organic topsoil. 16–54 and 16–55).5-foot-long dead stout stakes are required. .. ....... . . December 1996) .. ... ...Chapter 16 Figure 16–54 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Reed clump details .. ... . Cross section Not to scale Natural geotextile fabric wrap Backfill Mean high water elevation Backfill Dead stout stakes Coconut fiber roll (optional to reduce wave energy) Organic soil Plan Not to scale 3-6 feet Aquatic plant Dead stout stake 12-18 inches Optional coconut fiber roll 12-18 inches Mean water level Trench (filled with organic soil) 16–78 Lakebed (210-vi-EFH... December 1996) Part 650 Engineering Field Handbook Completing installation of reed clump system (Robbin B. Sotir & Associates photo) Figure 16–55b (210-vi-EFH. Sotir & Associates photo) Figure 16–55c Established reed clump system (Robbin B. Sotir & Associates photo) 16–79 .Chapter 16 Streambank and Shoreline Protection Figure 16–55a Installing dead stout stakes in reed clump system (Robbin B. can be molded to the curvature of the shoreline........ • Manufacturers estimate the product has an effective life of 6 to 10 years.. This material is most commonly manufactured in 12-inch diameters and lengths of 20 feet...Chapter 16 Streambank and Shoreline Protection (8) Coconut fiber roll Coconut fiber rolls are cylindrical structures composed of coconut fibers bound together with twine woven from coconut (figs. In addition to reducing wave energy. . oak stakes 16–80 (210-vi-EFH. this product can help contain substrate and encourage development of wetland communities. The fiber rolls function as breakwaters along the shores of lakes and embayments. • Flexible.... Figure 16–56 Part 650 Engineering Field Handbook Applications and effectiveness • Effective in lake areas where the water level fluctuates because it is able to protect the shoreline and encourage new vegetation. Coconut fiber roll details . 16–56 and 16–57). • Prefabricated materials can be expensive. .. December 1996) .. Cross section Vegetative plantings Not to scale Coconut fiber roll Mean high water elevation Eroded shoreline Lakebed 2 in. x 2 in. x 36 in.. . Figure 16–57 Coconut fiber roll system (210-vi-EFH. the fiber roll should be placed where it will not be overtopped by wave action.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Installation • Fiber roll should be located off shore at a distance where the top of the fiber roll is exposed at low tide. December 1996) 16–81 . Stakes should be placed on 4-foot centers and should not extend above the fiber roll. In nontidal areas. • If desired. • Drive 2 inch x 2 inch stakes between the binding twine and the coconut fiber. rooted cuttings can be installed between the coconut fiber roll and the shoreline. meandering. Army Corps of Engineers. and public policy. and David L. Great Britain. N. 1992. 1983. volumes I and II. Pagosa Springs. England. Washington. Stanley A. Washington. Davis. Harvey. Fish habitat structures: a selection using stream classification. and straight.G. Mike D. and Forrest Reynolds. Colorado. 1975. Water Resources Publications. Malanson.. DC.. Gary. pp. Restoration of aquatic ecosystems: science. Biotechnical slope protection and erosion control. David L. 1993. Schumm. U. 1991. Berger.D. U. Restoration. Section 32. William M. Richards. U. NY. 1984. Proceedings of the Fifth Federal Interagency Sedimentation Conference. and M. Leopold. Rosgen. Geographical Journal 14: 481-504. The fluvial system. Rosgen. A tentative classification of alluvial rivers. and Andrew T. 1963. Gray. E-29 through E-36. Pages C-31 through C-50 in Applied Fluvial Geomorphology. London. dynamics and control. CO. 200 pp. Van Nostrand Reinhold. 1990. Littleton. CO.S. The Pacific Rivers Council. Entrainment of gravel from naturally sorted riverbed material. Luna B. and pages E-29 through E-36 in Wildland Hydrology Consultants (Rosgen) Short Course. 1992. Geologic Survey Professional Paper 282-B. CO. The geographical cycle. September 28-October 2. and pages E-29 through E-36. AZ. Coppin. Public Law 93-251. Rosgen. George P. Flosi. Leiser. Wolman. Pages E-1 through E-28 in Applied Fluvial Geomorphology. September 28-October 2. 1889. A General Information Pamphlet. NY. 1993. David L. Main report. Schumm. Shore protection manual.. September 28-October 2. Watson. 1992. and Brenda Fittante. Riparian landscapes. Fisheries handbook of engineering requirements and biological criteria. Tucson. U. Pagosa Springs.J. DC. Andrews.S. 16–82 Rosgen. Leopold. and I.. final report to Congress on the Streambank Erosion Control Evaluation and Demonstration Act of 1974. Watershed management. Use of vegetation in civil engineering. Wildland Hydrology Consultants (Rosgen) Short Course. Dave. NV. Robert J. Butterworths. Las Vegas. braided. Leopold. 1985. 1992. NY. DC. Army Corps of Engineers.. 1991. Milo C. Bell. 1992.1603 References Naiman. Cambridge University. Army Coastal Engineering Research Center. Donald H. 1992. 1981. California salmonid stream habitat and restoration manual. 1977. (210-vi-EFH. Schumm. Stanley A. River channel patterns. Washington. John Wiley and Sons.S. Geologic Survey Circular 477. Stanley A. New York. December 1996) . A stream classification system—riparian ecosystems and their management.S. technology. Report for national research council committee on restoration of aquatic ecosystems in applied fluvial geomorphology. Incised channels: morphology. John.S. Pagosa Springs. Springer-Verlag. G. A sand county almanac and sketches here and there. E. Luna B. and Chester A. First North American Riparian Conference. Aldo. 1982. Entering the watershed. Wildland Hydrology Consultants (Rosgen) Short Course.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook 650. 1991. 1957. California Department of Fish and Game. Geological Society of America 94:1225-1231. 338 pp. U. Movement of bed material clasts in gravel streams. Help yourself—A discussion of erosion problems on the Great Lakes and alternative methods of shore protection. 1949. Streambank protection guidelines. 1977. U. Natl.S. December 1996) 16–83 . pp. Hdbk. Agricultural Information Bulletin 460.S. Department of Agriculture. U. The geomorphic approach to channel investigation. Vegetation for tidal shoreline stabilization in the Mid-Atlantic States. Soil Conservation Service. 1974. 1994. U. Stream habitat improvement handbook. Use of riprap for bank protection. 1992. 3-71 through 3-78.S. Soil Conservation Service.S. Technical Release 69. Gradation design of sand and gravel filters. Riprap for slope protection against wave action. Department of Agriculture. Department of Agriculture. U. Technical Release 56. 26. U. Department of Transportation. Highways in the river environment-hydraulic and environmental design considerations.S. 1991. Department of Agriculture. Forest Service. Soil Conservation Service. Department of Agriculture. Soil Conservation Service. A guide for design and layout of vegetative wave protection for earth dam embankments. U. Design of open channels.S. Soil Conservation Service.S.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook U. NV. 1983. Peter G.S. 1975. Proceedings of the Fifth Federal Interagency Sedimentation Conference. Southern Region.S. (need date) Waldo. part 633. Training and Design Manual.S. Army Corps of Engineers. Government Printing Office S/N001-007-00906-5. U. (210-vi-EFH.S. U. Eng. Las Vegas. Soil Conservation Service. U. Department of Transportation. Technical Release 25. U. Department of Agriculture. Department of Agriculture. 1983. ch. Chapter 16 16–84 Streambank and Shoreline Protection (210-vi-EFH. December 1996) Part 650 Engineering Field Handbook . Erosion control fabric Woven or spun material made from natural or synthetic fibers and placed to prevent surface erosion. The volume of water passing through a channel during a given time. The discharge that determines the stream's geomorphic planform dimensions. Current Dead blow hammer Deadman Deposition Discharge The flow of water through a stream channel. Dormant season The time of year when plants are not growing and deciduous plants shed their leaves. concrete. and flood plain. when unconfined. Modified or entrenched streams—The streamflow volume and depth that is the 1. fascines. The ground water contribution of streamflow. Cohesive soil A soil that. Bar Baseflow Bole A streambed deposit of sand or gravel. usually measured in cubic feet per second.to 3-year frequency flow event. banks. Channel A natural or manmade waterway that continuously or intermittently carries water. A hammer filled with lead shot or sand. December 1996) 16–85 . or aluminum sheet piling used to protect shorelines from wave action. Duration of flow Length of time a stream floods. Brushmattress A combination of live stakes.Glossary Bankfull discharge Natural streams—The discharge that fills the channel without overflowing onto the flood plain. The accumulation of soil particles on the channel bed. and branch cuttings installed to cover and protect streambanks and shorelines. Bulkhead Generally vertical structures of timber. steel. Branchpacking Live. branch cuttings and compacted soil used to repair slumped areas of streambanks. (210-vi-EFH. has considerable strength when air dried and significant strength when wet. often exposed during low-water periods. A log or concrete block buried in a streambank to anchor revetments. Trunk of a tree. woody. generally evident as falls or rapids. The development and upstream movement of a vertical or near vertical change in bed slope. December 1996) . filtration. Water contained in the voids of the saturated zone of geologic strata. Collapse or slippage of a large mass of streambank material. Fines Silt and clay particles. gravel. Volume of flow per unit of time. Littoral Littoral zone 16–86 Part 650 Engineering Field Handbook The sedimentary material of shorelines moved by waves and currents. water. passing over or through the soil. A wire mesh basket filled with rock that can be used in multiples as a structural unit. reinforcement. Filter A layer of fabric. or graded rock placed between the bank revetment or channel lining and soil to prevent the movement of fine grained sizes or to prevent revetment work from sinking into the soil. (210-vi-EFH. Foundation for a rootwad and boulders. Headcuts are often an indication of major disturbances in a stream system or watershed. usually expressed as cubic feet per second. or earth as an integral part of a product. A structure built perpendicular to the shoreline to trap littoral drift and retard erosion. blocks. A soil whose particles are easily detached and entrained in a fluid. Any permeable textile used with foundation soil. sand. rock. Flanking Flow rate Footer log Gabion Geotextile Groin Ground water Headcutting Streamflow between a structure and the bank that creates an area of scour. or gravity.Chapter 16 Streambank and Shoreline Protection Erosion Erosive (erodible) Failure The wearing away of the land by the natural forces of wind. or drainage. or other inert revetment units and into the underlying soil. either air or water. The most erodible soils tend to be silts and/or fine sands with little or no cohesion. An indefinite zone extending seaward from the shoreline to just beyond the breaker zone. structure. A log placed below the expected scour depth of a stream. Joint planting The insertion of live branch cuttings in openings or interstices of rocks. or system usually to provide separation. Littoral drift The movement of littoral drift either transport parallel (long shore transport) or perpendicular (on-shore transport) to the shoreline. that lacks significant internal strength and has little resistance to erosion. Riprap A layer. interlocking pavers. the stone used for this purpose. Reach A section of a stream's length. Removal of underwater material by waves or currents. such as sand. Piling A long. partly covered with soil. especially at the base or toe of a streambank or shoreline. or other armoring material shaped to conform to and protect streambanks or shorelines. The accumulation of sediment. Reed clump A combination of root divisions from aquatic plants and natural geotextile fabric to protect shorelines from wave action.Chapter 16 Streambank and Shoreline Protection Live branch cuttings Part 650 Engineering Field Handbook Living. elongated. facing. (210-vi-EFH. Live siltation construction Live branch cuttings that are placed in trenches at an angle from shoreline to trap sediment and protect them against wave action. The amount of sediment in transport. scour. Noncohesive soil Piling (sheet) Soil. Live fascine Bound. Live stake Live branch cuttings that are tamped or inserted into the earth to take root and produce vegetative growth. or protective mound of rubble or stones randomly placed to prevent erosion. Piping The progressive removal of soil particles from a soil mass by percolating water. heavy timber. Strips or sheets of metal or other material connected with meshed or interlocking members to form an impermeable diaphragm or wall. cylindrical bundles of live branch cuttings that are placed in shallow trenches. Revetment (armoring) A facing of stone. or metal support driven or jetted into the earth. and staked in place. freshly cut branches from woody shrub and tree species that readily propagate when embedded in soil. December 1996) 16–87 . Rootwad Scour Sediment deposition Sediment load Sediment A short length of tree trunk and root mass. concrete. or sloughing of a structure of embankment. leading to the development of flow channels or tunnels. also. Soil particles transported from their natural location by wind or water. Live cribwall A rectangular framework of logs or timbers filled with soil and containing live woody cuttings that are capable of rooting. The discharge that determines a stream’s geomorphic planform dimensions.Chapter 16 Streambank and Shoreline Protection Seepage Slumping (sloughing) Stream-forming flow Streambank Streambed (bed) Streamflow Submerged vanes Thalweg Toe Vegetated geogrid Vegetated structural revetments Vegetated structures 16–88 Part 650 Engineering Field Handbook The movement of water through the ground. Shallow mass movement of soil as a result of gravity and seepage. A retaining structure in which live plants or cuttings have been integrated. (210-vi-EFH. The bottom of a channel. Porous revetments. The movement of water within a channel. into which live plants or cuttings can be placed. Precast concrete or wooden elements placed in streambeds to deflect secondary currents away from the streambank. or water emerging on the face of a bank. The deepest part of a stream channel where the fastest current is usually found. Equivalent to the 1. The break in slope at the foot of a bank where it meets the streambed. The side slopes within which streamflow is confined. such as riprap or interlocking pavers. Live branch cuttings placed in layers with natural or synthetic geotextile fabric wrapped around each soil lift. December 1996) .to 3-year frequency flow event (see Bankfull discharge). Basic rock size is the D100 size. The curve was developed from empirical data to determine a rock size for a given velocity. is a direct reprint from the previous chapter 16.000 100 50 0 0 2 4 6 8 10 12 14 16 18 20 Velocity (ft/s) Based on Isbash Curve Procedure 1. Use velocity and fig. See figure 16A–1. The user can read the D100 rock size (100 percent of riprap ≤ this size) directly from the graph in terms of weight (pounds) or dimension (inches). because of its widespread acceptance and ease of use. Determine the design velocity.000 40 1. Engineering Field Manual. Rock size based on Isbash Curve Figure 16A–1 60 15. 2.000 Diameter of stone (in) 5.000 20 500 250 Weight of stone at 165 lb/ft3 10. (210-vi-EFH. Less experienced users should use this method for quick estimates or comparison with other methods before determining a final design. 16A-1 (Isbash Curve) to determine basic rock size. December 1996) 16A–1 .Appendix 16A Size Determination for Rock Riprap Isbash Curve The Isbash Curve. 3. 60 =0 C 0. Ratio of channel bottom width to depth (D) greater than 4. flow depth.8 K = .6 0. Determine the average channel grade or energy slope. Where a filter blanket is used. Basic rock size is the D75 size. stable foundation. 2.80 .5 2:1 :1 1 1/2 Side slope 0.90 0 5 = 0. Size of rock for which 25% by weight is larger Ds = 3.0 Ds = D75 size rock in inches c 10 = .010 0.72 . Ds (nominal diameter in inches).90 1. Part 650 Engineering Field Handbook p De o f fl 40 Streambank and Shoreline Protection Notes: 1.75 0. 16A-2 with energy slope.4 46 (210-vi-EFH.63 .0 Ratio of curve radius to water surface width = 30 9 Rc=Curve radius Ws=Water surface width S=Energy slope or channel grade w=62. December 1996) R c / Ws 4-6 6-9 9-12 straight channel 10 10 8 ) o th w D 6 (ft 3:1 4 2 0. design filter material grading in accordance with cirteria in NRCS Soil Mechanics Note 1.015 Channel slope S (ft/ft) 7 0. 2.5 w D S CK Chapter 16 16A–2 Rock size based on Far West States (FWS)-Lane method Figure 16A–2 .005 0.7 K . and minimum section thickness (normal to slope) not less than Ds at maximum water surface elevation and 3 Ds at the base.52 . Enter fig. and site physical characteristics to determine basic rock size. Additional requirements for stable riprap include fairly well graded rock.72 =0 2 = 0.020 Procedure 1. 3. 4.87 St ra 20 ig ht ch an ne l 912 6- Slide slope 1 1/2:1 1 3/4:1 2:1 2 1/2:1 3:1 .56. 3. Specific gravity of rock not less than 2. 0 1 (K) 0.18 Determine gradation limits Example: Calculate basic rock size from one of the design methods.4 d= 16 in. (from figure 16A-2) 4. d low/high= ––––––––—— K KD 6 40 5 D50 3 Rock Riprap Gradation 4 Reference Size D75 D100 5 50 60 70 80 Gradation limits curve for determining suitable rock gradation 7 90 100 Figure 16A–3 Chapter 16 Part 650 Engineering Field Handbook 10 9 9 3 1 16A–3 .=calculated basic rock size from one of the rock riprap design methods d low/high=lower or upper size limit of riprap 7 30 4 D30 2 D100. D75. (K) 1.18 8 0 10 Streambank and Shoreline Protection 20 KD=K from lower gradation limits curve for the D50. 75 etc. 75 etc.18 60 40 20 d 100 755.2 0.25 6 0.0 27 in 24 in 21 in 18 in 14 in 17 in 16 in 15 in 13 in 8 in upper lower KD=1. D100 etc.8 1. December 1996) 2 0.0 Determine KD from lower curve KD=1. D100. For this example assume D75=16 in.6 8 0.% Passing (by weight) (210-vi-EFH. . Soil preference—Indication of the type of soil the plant prefers: sand. Table header definitions (in the order they occur on the tables): Scientific name—Genus and species name of the plant. AQ. Flood tolerance—Selective rating of the ability of the plant to tolerate flooding events. Taxonomy. Maximum water depth—The maximum water depth the plant can tolerate and not succumb to drowning. WV. etc. KS. CZ. MS. legume. AR 3 North Central—MO. Region of occurrence—Region(s) of occurrence using the regions of distribution in PLANTS (Plant List of Attributes. (210-vi-EFH. DE. fibrous. Notes—Other important or interesting characteristics about the plant. clay. IL. AL. KY. VA. SD. MT (eastern) WY (eastern) 5 Central Plains—NE. Flood season—Time of the year that the plant can tolerate flooding events. MN. medium. Minimum water depth—The minimum water depth required by the plant for optimal growth. YQ Commercial availability—Answers whether the plant is available from commercial plant vendors. LA. etc. IA. MI. FL. Plant materials—The type of vegetation plant parts that can be used to establish a new colony of the species. Region code number or letter: 1 Northeast—ME. good. Wetland indicator—A national indicator from National List of Plant Species that Occur in Wetlands: 1988 National Summary. MT (western) WY (western) 0 California—Ca A Alaska—AK C Caribbean—PR. Further subdivision of the listing should be considered to account for local conditions and identify species suitable only for soil bioengineering systems. WI. December 1996) 16B–1 . MQ. TQ. CT. MD. VI. Drought tolerance—Subjective rating of the ability of the plant to survive dry soil conditions. etc. IQ. pH preference—Lists the pH preference(s) of the plant. OK 7 Southwest—AZ. OH 2 Southeast—NC. Deposition tolerance—Subjective rating of the ability of the plant to tolerate deposition of soil or organic debris around or over the roots and stems. VT. forb. Common name—Common name of the plant. Plant type—Short description of the type of plant: tree. MA. fast. GU. CO (eastern) 6 South Plains—TX. shrub. NY. Nomenclature. Spread potential—Subjective rating of the potential for the plant to spread: low. SQ H Hawaii—HI. UT. NJ. Establishment speed—Subjective rating of the speed of establishment of the plant. NH. PA. Root type—Description of the root of the plant: tap. etc. Growth rate—Subjective rating of the speed of growth of the plant: slow. CO (western) 9 Northwest—WA. TN. suckering. 1994). and Symbols. grass. NM 8 Intermountain—NV. etc. SC. loam.Appendix 16B Plants for Soil Bioengineering and Associated Systems The information in appendix 16B is from the Natural Resources Conservation Service's data base for Soil Bioengineering Plant Materials (biotype). Rooting ability from cutting—Subjective rating of cut stems of the plant to root without special hormone and/or environmental surroundings provided. RI. WQ. IN 4 North Plains—ND. ID. OR. The plants are listed in alphabetical order by scientific name. GA. Shade tolerance—Subjective rating of the ability of the plant to tolerate shaded sites. shrub to fibrous. 8 Acer glabrum Acer negundo Acer rubrum Acer saccharinum yes yes poor fair to good (210-vi-EFH. Notes plants plants Plants occur mostly east of the 95th parallel. suckering small tree yes. Use in sun & part rooted shade.0. spreading. Survived cuttings deep flooding for one season in Pacific NW.8. but small rooting in tree at nodes limited quantities Rooting ability from cutting Acer circinatum Root type Region occurence Common name Scientific name Commer.3. grows in poor soils. plants plants Plant materials type Streambank and Shoreline Protection medium shallow. 4. Occurs on and prefers sites with a high water table and/or an annual flooding event. Survived 2 years of flooding in MS.0 dwarf maple 4.3.5.2. 4. Branches often touch& root at ground level. 6 vine maple boxelder red maple silver maple 1.9. Occurs British Columbia to CA. 0 1.2. plants.9. A 1.3.Plant type cial availability Woody plants for soil bioengineering and associated systems Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook .6. poor medium moderatetree ly deep.5.2. tree fibrous medium shallow tree small to fibrous. December 1996) poor poor fast when young fast when young fast slow Growth rate medium medium fast slow Establishment speed fair good fair good Spread potential usually dioecious.5.16B–2 yes yes 9. 8.6. 7. Not tolerant of high pH sites.7. Often occurs with conifer overstory. Roots have relation with nitrogen-fixing actinomycetes. Usually grows west of the Cascade Mtns. A nitrogen source.Plant type cial availability Common name Scientific name Region occurence Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–3 . Notes Streambank and Shoreline Protection large shrub medium tree tree Rooting ability from cutting pacific alder Root type Alnus pacifica Commer.A red alder smooth alder 1.to 12-foot spacing.6 Alnus rubra Alnus serrulata (210-vi-EFH. May be seedable.3. Survived 2 years of flooding in MS. needs full sun. suckering poor poor to fair poor slow fast most alders are fast Growth rate medium fast Establishment speed fair good Spread potential plants plants plants Plant materials type Thicket forming. Short lived species.2. A species for forested wetland sites in the Pacific northwest.400 feet elevation. 5. spreading. Susceptible to caterpillers. December 1996) shallow. Plant on 10.0. within 125 milesof the ocean & below 2. susceptible to ice damage.yes yes 9. spreading shallow. NV. & UT. May produce fruit in second year. 7. & eastern OR. 6 utah serviceberry false indigo red chokeberry Amorpha fruitcosa Aronia arbutifolia 9 cusick’s serviceberry Amelanchier alnifolia var cusickii Amelanchier utahensis 9. A different variety is Pacific serviceberry A. Notes Streambank and Shoreline Protection yes yes yes yes. seed plants plants plants Plant materials type Rhizomatous.2.6.3.2.A shrub shrub small to large shrub shrub poor poor poor poor fair to good Spread potential fast medium fast fast poor medium medium medium rapid medium first year. Host to several insect & disease pests. alnifolia var semiintegrifolia.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . seed plants.sinuata Root type Region occurence Common name Scientific name Commer.8. 4.5. Occurs in southeast OR.0. Usually seed propagated. Has been seeded directly on roadside cut and fill sites in MD. A nitrogen source. Occurs AK to CA. Supposedly root suckers. December 1996) 9 1.3. but shrub to shallow very small tree limited quantities Growth rate sitka alder Rooting ability from cutting Alnus viridis ssp.16B–4 (210-vi-EFH. moderate thereafter Establishment speed plants. Occurs in eastern WA. south ID. northern ID.0 1. 6 6. cuttings fascines. unisexual plants. Occurs MA to FL & TX. thickets where plants native & can be propagated by layering & root cuttings. fibrous tap and root suckers fibrous. 0 seepwillow eastern baccharis coyotebush water wally Baccharis glutinosa Baccharis halimifolia Baccharis pilularis Baccharis salicifolia yes yes yes (210-vi-EFH.8. Colonyforming to 1 foot high in CA coastal bluffs. brush mats.3. cuttings fascines.6 9.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–5 .8. widespreading good good good good poor to fair fair fast fast Establishment speed fair fair fair poor Spread potential Notes Thicket forming. May be seedable. December 1996) fibrous deep & widespreading.2. 5. deep. plants root Does produce cuttings. stakes.7. many forms prostrate & spreading. spray. stakes. brush Thicket forming. fascines.0 6. Was B.1. glutinosa. layering. Pioneer in gullies. plants. layering. Occurs NY to FL & TX. 0 1.7.2. Resistant to salt cuttings. mats. unisexual plants. Plant materials type Streambank and Shoreline Protection medium evergreen shrub medium fibrous evergreen shrub medium shrub medium shrub small tree Growth rate pawpaw Rooting ability from cutting Asimina triloba Root type Region occurence Common name Scientific name Commer. 4. Plants coppice when cut.7.0. May be B.A 1. brush mats.9.4.5. Survived 1 year of flooding in MS. Not tolerant of more than a few days inundation in a New England trial.2. A 1.9 water birch paper birch low birch Betula papyrifera Betula pumila 1. Occurs on the Pacific Coast to CO.16B–6 4.6 river birch Betula nigra Betula occidentalis 6. 5.9. layering.3.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook .3. cuttings Plant materials type Streambank and Shoreline Protection small to large shrub medium tree medium tree medium to large tree medium evergreen shrub Growth rate mulefat baccharis Rooting ability from cutting Baccharis viminea Root type Region occurence Common name Scientific name Commer. fascines. 8. 8. fibrous fibrous.8.3. Hybridizes with B papyrifera. December 1996) fibrous shallow.7. 5. salicifolia. stakes. 0 yes yes yes (210-vi-EFH. spreadin g fibrous poor poor poor good fast when fast young fast when fast young Establishment speed poor poor Spread potential Notes plants plants plants plants Occurs Newfoundland to NJ & MN. Short lived but the most resistant to borers of all birches. 3. A northern form occurs from New England to NC & west to MN & AR. A species for forested wetland sites.3.7 bitternut hickory shagbark hickory southern catalpa Carya cordiformis Carya ovata (210-vi-EFH.2. Occurs MD to FL & west to southern IL & east TX.5.6 1. 6 Carya aquatica yes.3. OH. Hard to transplant. 5. December 1996) Catalpa bignonioides yes tree medium tree tree tall tree tap tap & dense laterals tap to shallow lateral poor poor poor poor poor fair slow slow slow slow fair slow fast slow Establishment speed poor poor poor poor poor Spread potential plants plants plants plants plants Plant materials type Occurs in SW GA to LA.6 1. small limited tree sources Growth rate american hornbeam Rooting ability from cutting Carpinis caroliniana Root type Region occurence Common name Scientific name Commer. MI. & TX. Not tolerate flooding in a MO trial. Occurs Quebec to FL & TX. naturalized in New England. Not tolerant of flooding in TN Valley trial.1.2.2. 5. 6 yes 1.3. Occurs Quebec to FL & LA.3. Notes Streambank and Shoreline Protection yes yes water hickory 1.2. 4.2. Roots & stumps coppice.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–7 .6. Transplants with difficulty. Survived 3 years of flooding in MS.5. plants plants plants Plant materials type Occurs TX to southern CA & into Mexico.0 1. 5.3.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . Leaf fall allelopathic.6. 0 Celtis occidentalis Cephalanthus occidentalis Cercis canadensis Chilopsis linearis yes yes yes (210-vi-EFH.3.8.16B–8 yes yes 1.6.7. west to TX & southern IN.2. 8 hackberry buttonbush redbud desert willow 6. 9. 5. Juvenile wood & roots will root. 8. Very resistant to witches-broom. Survived 2 years of flooding in MS.7.3. layering.0 1.2.3.' 'Hope. December 1996) shrub fibrous tap medium to deep fibrous relatively shallow poor fair to good poor poor low low slow poor medium poor slow slow Spread potential medium medium low slow slow medium to fast medium Establishment speed plants plants brush mats.6. Also in Mexico.7.' & 'Regal' cultivars were releasedin New Mexico.6. Not tolerate more than a few days inundation in a MO trial. 5.7. 4. Notes Streambank and Shoreline Protection small tree large shrub medium tree medium tree Growth rate sugarberry Rooting ability from cutting Celtis laevigata Root type Region occurence Common name Scientific name Commer.2. Will grow in sun or shade. Occurs FL. 'Barranco. Susceptible to witches-broom. 8 1. Occurs Quebec to NC & AL.2. 5. salt tolerant on coastal sites. spreading shallow.9.2. plants fascines. cuttings. brush mats.2. 8. December 1996) large shrub small shrub shrub vine small tree root suckering. 'Indigo' cultivar was released by MI PMC.5.2. fibrous shallow & fibrous fair fair poor poor poor fast slow fast slow good poor Spread potential fair medium poor fast Establishment speed fascines.6 1. 4.6 1. brush mats.6 sweet pepperbush silky dogwood roughleaf dogwood Cornus amomum Cornus drummondii 1.2. Produces new plants from layering in sandy soils at 7to 8-inch precip & 1. Occurs Saskatchewan to KS & NE.000-foot elevation. stakes. Notes Streambank and Shoreline Protection yes yes yes yes yes Growth rate fringetree Rooting ability from cutting Chionanthus virginicus Root type Region occurence Common name Scientific name Commer. layering. & TX.4.3. plants plants plants plants Plant materials type Root suckers too. south to MS.3. Susceptible to severe browsing & scale. 4. tolerates partial shade.7.2. Pith brown. 6 (210-vi-EFH. stakes. Occurs ME to FL. LA. cuttings.3. Has rhizomes.0 western clematis Clematis ligusticifolia Clethera alnifolia 1. layering.1.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–9 . Pith usually brown. 5.6. Occurs PA to FL & west to TX. Use in cuttings. fascines.3. fascines.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 fair Establishment speed fair poor Spread potential Hard to transplant as bare root. plants Plant materials type Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook . fibrous shallow. Occurs Nova Scotia to VA & ND.2. tolerates city smoke.5.2. layering. coppices freely. Pith white.3. cuttings.3 gray dogwood 1. December 1996) roundleaf dogwood Cornus rugosa 1.6 stiff dogwood 1. combination with plants species with root_abil = good to excellent. 5. 4. Not tolerant of flooding in TN Valley trial. stakes.6 Cornus foemina Cornus racemosa 1.3. plants racemosa Occurs VA to FL & west to TX. Occurs ME & MN to NC & OK. Formerly C. Pith white. plants fascines.6 yes yes medium to small shrub medium to small shrub medium shrub small tree shallow. Pith usually brown.2. fibrous fair to good fair fair poor medium fast fair Growth rate flowering dogwood Rooting ability from cutting Cornus florida Root type Region occurence Common name Scientific name Commer. fibrous shallow.5.16B–10 (210-vi-EFH. Notes Forms dense thickets. brush mats. 4. 'Ruby' cultivar was released by NY PMC.6. Forms dense plants thickets on moist sites.7. AR & MS. 0. Formerly C. foemina. Grown from seed or grafted.3.4. brush mats. plants fascines. stolonifera. Forms thickets by rootstocks & rooting of branches. plants Plant materials type Streambank and Shoreline Protection yes shrub swamp dogwood medium shrub Cornus stricta yes yes Growth rate red-osier dogwood Rooting ability from cutting Cornus sericea ssp sericea Root type Region occurence Common name Scientific name Commer. stakes.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–11 .2. cuttings. 'Homestead' cultivar was released by ND PMC.1.9. Prefers organic sites.A (210-vi-EFH.0. 5. Pith white. C downy hawthorn titi Crataegus mollis Cyrilla racemiflora small tree tree small tree 3.8.5.8. Occurs Ontario & MN to AL. layering. December 1996) 1. cuttings. a good honey plant. Occurs VA to FL & on to South America.3.6 1. Survived 6 years of flooding in MS.A douglas hawthorn Crataegus douglasii tap tap to fibrous shallow poor poor to fair poor to fair poor good slow fast Spread potential poor medium fair Establishment speed May be same as C. Notes plants plants Semievergreen. 4. Occurs British Columbia to CA & MN. 9.2. tolerates partial shade. 6 swamp privet 1. 8. Thicket forming.A silverberry Elaeagnus commutata Forestiera acuminata 1.3.6 Growth rate persimmon Rooting ability from cutting Diospyros virginiana Root type Region occurence Common name Scientific name Commer.9 1.2. Survived 3 years of flooding in MS. 8. 'Cardan' cultivar was released by ND PMC.16B–12 (210-vi-EFH. 4.4.6 carolina ash Fraxinus caroliniana yes yes yes yes yes medium tree medium tree large tree large shrub to small tree small tree medium tree poor fair poor to fair poor shallow.2.3. Stoloniferous & tap rooted. 5.0 oregon ash Fraxinus latifolia 1. Occurs CT toFL & TX. Occurs in swamps VA to TX.6. Easily transplanted. fibrous fibrous shallow. Notes Streambank and Shoreline Protection Fraxinus green ash pennsylvanica 1. Usually occurs west of the Cascade Mtns.3. December 1996) 9. fibrous poor moderately poor shallow.5. May be grown from seed but usually grafted.2. Grows well in limestone & alkaline soils.2.9.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . fibrous tap fast fast when young fast slow fast slow poor fair poor Spread potential fast good medium fair fast fast fair Establishment speed plants plants plants plants plants plants Plant materials type Survived 3 years of flooding in MS. Forms dense thickets on dry sites.3. C oceanspray sweet gallberry Ilex coriacea yes small to large shrub yes.9. Native ecotypes have thorns! Notes Streambank and Shoreline Protection Holodiscus discolor yes yes halberd-leaf marshmallow Hibiscus laevis Hibiscus hibiscus moscheutos ssp.6 1.6.6.0 1. Often pioneers on burned areas.9 Growth rate honeylocust Rooting ability from cutting Gleditsia triacanthos Root type Region occurence Common name Scientific name Commer. shrub shrub shrub shrub medium tree deep & widespread poor poor to fair poor poor poor poor poor to fair medium to rapid fast fast fast Establishment speed poor medium Spread potential plants plants plants plants plants plants plants Plant materials type Evergreen.3. Survived deep flooding for 100 days 3 consecutive years. 4.2. Occurs from British Columbia to CA to ID.2. Usually grown from seed or cuttings. 0 Hibiscus moscheutos 9. militaris. shrub from contract growers.8.3. December 1996) common rose 1.6. 7.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–13 .5. mallow 5.2.8. Has been used in reg_occ 7.7.lasiocarpos yes hibiscus yes yes Hibiscus aculeatus 2.(210-vi-EFH. Was H. 6 yaupon black walnut 1. Though drought tolerant. Prefers seasonally flooded sites.3. Evergreen.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook .2.2. 6 winterberry Ilex verticillata yes 1.2. Not tolerate flooding in TN Valley trial.2. 6 american holly Ilex opaca yes yes yes Growth rate possomhaw Rooting ability from cutting Ilex decidua Root type Region occurence Common name Scientific name Commer.3. 4. Stoloniferous! Occurs eastern US & Canada.2. Root suckers.6 bitter gallberrry Ilex glabra yes yes 1.6 1.16B–14 1.5.3. 5. Plants dioecious. December 1996) Juglans nigra Juniperus virginiana tap & deep & widespread laterals tap root & prolific laterals large tree tap & dense fibrous laterals medium tree large shrub small to large shrub small tree small shrub large shrub to small tree poor poor poor poor poor poor poor slow fair slow slow slow slow Spread potential poor medium good fair medium poor Establishment speed plants plants plants plants plants plants plants Plant materials type Not tolerate flooding in TN Valley trial. 4. Survived 3 years of flooding in MS.6 yes 1.6 eastern redcedar Ilex vomitoria (210-vi-EFH.3. will not grow on poor or dry soil sites.2.5. Notes Streambank and Shoreline Protection 1. Easy to transplant when young.2.3. sprouts after fire. c 1. Occurs in swamps from MA to FL and west to east TX.2. east to FL & north to NJ. Occurs east TX & OK. A species for forested wetland sites.6. Evergreen.1.0. Notes Streambank and Shoreline Protection yes yes yes yes yes yes yes Growth rate leucothoe Rooting ability from cutting Leucothoe axillaris Root type Region occurence Common name Scientific name Commer.7. Prefers acid soils. stakes. 6 black twinberry fetterbush sweetbay southern waxmyrtle swamp tupelo Lonicera involucrata Lyonia lucida Magnolia virginiana Myrica cerifera Nyssa aquatica 1. fibrous small shrub small tree small to large shrub small to large shrub large tree large tree shrub small to large shrub poor poor poor poor good poor poor poor poor fast fast slow medium slow slow fast fast slow slow slow Establishment speed slow poor to fair fair Spread potential plants plants plants plants fascines.2.8.6 1. plants plants plants plants plants Plant materials type Trees from the wild do not transplant well. 6 sweetgum Liquidambar styraciflua tulip poplar 1. Evergreen.2.A 1. Dioecious.6 3. Evergreen.2 1. 5.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–15 .2.3.2. 9. 5. cuttings.6 spicebush Lindera benzoin Liriodendron tulipifera 1. Hard to transplant. December 1996) yes fibrous fibrous & shallow deep & widespreading tap to fibrous large tree shallow.2 (210-vi-EFH.3.3.3.2. Notes Streambank and Shoreline Protection yes yes yes large shrub to small tree Growth rate ogeeche lime Rooting ability from cutting Nyssa ogeeche Root type Region occurence Common name Scientific name Commer.6 hophornbeam redbay lewis 9.6 1. fibrous. Difficult to transplant but plant in sun or shade on 10.16B–16 1.5.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook .0 mockorange Persea borbonia Philadelphus lewesii 1. Difficult to transplant. Only grows close to perennial wetland sites.2. A species for forested wetland sites. very long.to 12-foot spacing.2. fibrous poor poor poor poor poor fast slow slow Spread potential medium medium to fast slow slow fair medium poor medium slow slow Establishment speed plants plants plants plants plants Plant materials type Usually grown from seed. decending sparse. 4.3.2. 6 blackgum Nyssa sylvatica Ostrya virginiana 2 (210-vi-EFH. December 1996) yes large shrub small to large evergreen tree small tree tall tree fibrous sparse.3. Largest fruit of all Nyssa. Tolerated flooding for up to 30 days during 1 growing season. Vegetative reproduction not noted. 3.9 1.2.9.2. west to IL & TX. lateral shallow but with rhizomes fibrous poor poor fair fair good fairly fast fast slow fast slow Establishment speed poor poor Spread potential Notes plants plants fascines. 6 1. A (210-vi-EFH. cuttings.5.9 mallow ninebark Physocarpus malvaceus Physocarpus opulifolius 8. Usually occurs brush west of the Cascade mats. layering.6 common ninebark loblolly pine water elm Pinus taeda Planera aquatica 8.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–17 .2. fascines. layering. cuttings. plants Occurs KY to FL.0. Propagated by seed plants or cuttings.3.1. 5. brush mats. Use in combination with other species with rooting ability good to excellent. cuttings.3.6. December 1996) yes yes yes yes short tap changes to shallow spreading laterals shallow. plants Plant materials type Streambank and Shoreline Protection small tree medium tree medium shrub small shrub large shrub Growth rate pacific ninebark Rooting ability from cutting Physocarpus capitatus Root type Region occurence Common name Scientific name Commer. 4. 8. Usually occurs east of the Cascade Mtns. Mtns. layering. stakes. Plant on 10.2. 0 1. yes 4.16B–18 1. plants fascines. in ID for riparian poles. sites.8.2.6 0 4. Transplants well. brush mats.8.9. fibrous shallow fibrous.5. 5. December 1996) deep.O.3. Notes fascines. A species for forested wetland sites.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . cuttings. poles. widespreading v good v good poor fast fast fast fast Establishment speed medium Spread potential A species for forested wetlands sites in CA. 9. Under development stakes. cuttings.6. layering.5. 7. plants plants plants Plant materials type Streambank and Shoreline Protection tall tree large tree tall tree large tree Growth rate sycamore Rooting ability from cutting Platanus occidentalis Root type Region occurence Common name Scientific name Commer. Tolerates city smoke & alkali sites. brush mats.3.to12-foot spacing.A California sycamore narrowleaf cottonwood balsam poplar Platanus racemosa Populus angustifolia Populus balsamifera yes (210-vi-EFH. root suckers. brush mats.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–19 . layering. stakes. Use rooted plant materials. profuse suckers.5. Dirty tree. brush mats. A pioneer species on sunny sites. root cuttings. Not tolerant of more than a few days inundation in a New England trial.8.7. fascines.6. fibrous.6.3.2.2. Normal propagation is by root cuttings.9.3. plants Short lived. plants fascines. Tolerates saline stakes. cuttings. Plant roots may be invasive. 7.0. Hybridizes with several other poplars. Survived over 1 year of flooding in MS. 4. layering. fibrous shallow. poles. vigorous underground runners shallow. poles.7. soils. December 1996) shallow. 8.5. cuttings. 0 1. 4.9 yes yes (210-vi-EFH. suckering poor to fair v good v good fast fast fast fast fast Establishment speed fair poor Spread potential Short lived. Endures heat & sunny sites. plants Plant materials type Streambank and Shoreline Protection medium tree tree tall tree Growth rate eastern cottonwood Rooting ability from cutting Populus deltoides Root type Region occurence Common name Scientific name Commer.8. A fremont cottonwood quaking aspen Populus fremontii Populus tremuloides 1. May be sensitive to aluminum in the soil. Notes layering. 2.6. Plant on 5. Usually grown from seed.8. Thicket forming. Under development in ID for riparian sites. chokecherry 4. 'Rainbow' cultivar released by Knox City. Was P. Plant on 10. Has hydrocyanic acid in most parts.16B–20 4.3.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 plants plants. balsimifera Notes Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook . stakes. especially the seeds.0. 0.A yes yes 1. root cuttings fascines.9. December 1996) large shrub small shrub large tree v good shallow. May be P. 7. A species for forested wetland sites. suckering deep & widespread. 5. brush mats. poles.6 wild plum common 1. 9. cuttings. PMC.7. suckering poor fibrous. Usually grown from cuttings.2.to 8-foot spacing.5. Thicket forming.to 12foot spacing. layering. Reportedly poisonous to cattle.3. trichophora.A Prunus angustifolia Prunus virginiana yes (210-vi-EFH. plants Plant materials type A species for forested wetland sites. TX. fibrous fast Establishment speed good good Spread potential medium medium fair medium fast fast Growth rate black cottonwood Rooting ability from cutting Populus trichocarpa Root type Region occurence Common name Scientific name Commer. poor spreading.8. 6 1. in the Columbia River Gorge to the Dalles & to Yakima. 5.6 9. Notes Streambank and Shoreline Protection yes yes yes yes yes Growth rate white oak Rooting ability from cutting Quercus alba Root type Region occurence Common name Scientific name Commer. Often used as a street tree in the southeast US.2. 4. 'Boomer' cultivar released by TX PMC. 9 swamp white oak oregon white oak swamp laurel oak overcup oak bur oak Quercus bicolor Quercus garryana Quercus laurifolia Quercus lyrata (210-vi-EFH. Usually grows west of the Cascade Mtns.3. Often worthless as a lumber species.2.6 1. December 1996) Quercus macrocarpa large tree medium tree tree shrub to large tree medium tree large tree deep tap & welldeveloped laterals tap deteriorates to dense shallow laterals tap deep tap & welldeveloped laterals somewhat shallow tap to deep.1.5.2.3.6 1.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–21 . Difficult to transplant larger specimens. Propagated from seed sown in fall.2.2.3. Survived 2 years of flooding in MS. welldeveloped fibrous poor poor poor poor poor poor slow Spread potential slow fast slow poor slow fair medium fair slow medium fast slow fast slow fast slow Establishment speed plants plants plants plants plants plants Plant materials type Survived 2 years of flooding in MS. WA.3. Did not survive more than a few days flooding in a trial in New England.6. 5.0 1. to 12-foot spacing.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . Easily transplanted. 6 cherrybark oak pin oak willow oak shumard oak 1. fibrous welldeveloped fibrous laterals after taproot disintegrates shallow & spreading tap & deep laterals poor poor poor poor poor poor poor fast fair poor poor Spread potential good by stolons low medium fair fast slow fair medium slow fast fast fast on good sites fair Establishment speed plants plants plants plants plants plants plants Plant materials type Mat forming from suckers & stolons.6 Quercus pagoda Quercus palustris Quercus phellos Quercus shumardii 1. Notes Streambank and Shoreline Protection Rhododendron coast azalea atlanticum yes 1. 6 water oak Quercus nigra yes small shrub large tree medium to large tree large tree tree medium tree medium tree shallow shallow. Occurs from DE to SC.2. Easily transplanted.3.2.2.3. December 1996) 1. Plant on 10. 6 Growth rate swamp chestnut oak Rooting ability from cutting Quercus michauxii Root type Region occurence Common name Scientific name Commer.2.3.2.2 yes 1. Survived 2 years of flooding in MS.3.16B–22 (210-vi-EFH. 5. A species for forested wetland sites. 5.3.6 1. is by root cuttings plants or seed. 4.3.7. plants cuttings. 7.9.3. suckering fibrous.5. December 1996) smooth sumac flameleaf sumac 9. 0.6 1. suckering Root type fair to good fair to good poor poor to fair poor to fair poor Rooting ability from cutting fast fast Establishment speed medium fast to fast fast fast slow Growth rate good fair to good fair Spread potential Has stoloniferous forms. plants root Normal propagation cuttings.5.2.0 7.6. Reported toxic to livestock.8. root Thicket forming. Not tolerant of flooding in TN Valley trial. root suckers.8.9 1.3. Occurs from ME to SC. 0 1.2. cuttings.2 yes yes yes shrub shrub medium tree large shrub medium shrub shrub shallow fibrous. Highly susceptible to insects & diseases. 7.5. A browsed species. cuttings.A baldhip rose nootka rose Rosa nutkana 1. plants plants Plant materials type Streambank and Shoreline Protection Rosa gymnocarpa Robinia black locust pseuodoacacia Rhus glabra Rhus copallina Rhododendron swamp viscosum azalea Commer.8.9. A browsed species. 4. root suckers. plants root Thicket forming.0. Escaped in regions 5.Plant type cial availability Common name Scientific name Region occurence Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–23 .2.6. 4.8.9.(210-vi-EFH. Notes cuttings. 4. Normal propagation is by root cuttings.7.3. plants plants fascines.A 1.16B–24 small shrub small shrub small shrub 1.8.9. December 1996) good good good fair to good good good fair fast Establishment speed fair Spread potential Notes plants plants plants Normal propagation is by root cuttings.6.2.0 virginia rose woods rose allegheny blackberry red raspberry 1. 4.3 3.0. 5 1.3. A browsed species. Use in combination with other species.0.6.5.2. strigosus. 6. 7. A salmonberry 9.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . cuttings. strigosus Rubus spectabilis yes shrub small shrub small shrub (210-vi-EFH. 5. 9. Was R. Rooting ability is good to excellent.3. plants Plant materials type Streambank and Shoreline Protection fibrous fibrous fibrous rhizomatous & fibrous shallow Growth rate swamp rose Rooting ability from cutting Rosa palustris Root type Region occurence Common name Scientific name Commer.2.8.2. Normal propagation is by root cuttings.A Rosa virginiana Rosa woodsii Rubus allegheniensis Rubus idaeus ssp.5. stakes. plants fascines.not yes native 1. Notes fascines.9 1.A 7 peachleaf willow bebb's willow pussy willow Salix amygdaloides Salix bebbiana Salix bonplandiana yes yes shallow (210-vi-EFH.8.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–25 . Eaten by livestock stakes.6.3. brush mats. Under development in ID for riparian sites.5. 7. 4. poles. plants cuttings. stakes. layering.3. Hybridized with several other willow species. Plant plants on 2' to 6' spacing.2. brush mats.7. Not tolerant of shade. Not a native species. when young. layering. May be short-lived. poles. layering. cuttings.8. 5. cuttings. Does not form plants suckers. fascines. 9. cuttings. ‘Bankers’ cultivar released by Kentucky PMC.4. December 1996) v good v good v good fast fast medium fast Establishment speed poor Spread potential Often roots only at callus cut. plants Plant materials type Streambank and Shoreline Protection medium fibrous shrub to large tree small fibrous shrub to large tree large shallow shrub to to deep small tree small shrub Growth rate dwarf willow Rooting ability from cutting Salix X cottetii Root type Region occurence Common name Scientific name Commer. brush mats. Usually east of the Cascade Mtns & in ID & MT. layering. it may be S.9. December 1996) 7. brush mats. 0 1.8.3.6. Use on sunny to stakes. cuttings. Notes fascines. 0. rhizomatous fibrous shallow. layering. cuttings. fascines. A botanic discrepancy in the name. Cascade Mtns. 7. drummondiana willow 0 8.2. plants Plant materials type Streambank and Shoreline Protection yes yes yes yes shrub Growth rate booth willow Rooting ability from cutting Salix boothii Root type Region occurence Common name Scientific name Commer. Under development in ID for riparian sites.2. 4. plants fascines.9.8. spreading good v good good v good fast rapid fast Establishment speed Spread potential Under development in Idaho for riparian sites. stakes. poles.5. 4.9 pussy willow Salix discolor (210-vi-EFH. ligulifolia! 'Placer' cultivar released by OR PMC.8.9. poles. fascines. plants Relished by livestock. partial shade sites. plants Under development in ID for riparian sites. 'Curlew' cultivar released by WA PMC.A erect willow coyote willow Salix eriocephala Salix exigua Salix drummond's 7. stakes.9 medium shrub large shrub shrub large shrub shallow.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . suckering.16B–26 1. layering. Usually east of the cuttings.3. fibrous. poles. cuttings. 'Silvar' cultivar released by WA PMC. Plant materials type Streambank and Shoreline Protection medium shrub large fibrous. Relished by livestock. 0 9. Thicket forming. stakes.8. layering. Can compete well with grasses. poles. plants fascines.5. cuttings. brush mats. medium thereafter fast Establishment speed Spread potential Notes May have salt tolerance. stakes. December 1996) fibrous. cuttings. shrub to dense small tree small shallow shrub to to deep large tree small to large shrub Growth rate geyer's willow Rooting ability from cutting Salix geyeriana Root type Region occurence Common name Scientific name Commer. fascines. 4. Some say this is western black willow. brush mats. poles. Occurs east of the plants Cascade Mtns at higher elevations. poles.7. 'Clatsop' cultivar was released by OR PMC.0 1.3.6 goodding willow hooker willow prairie willow Salix gooddingii Salix hookeriana Salix humilis yes (210-vi-EFH. stakes. spreading good v good good to excel fast medium rapid medium when young.7. 0 6. Under development in ID for riparian sites. plants fascines.9. plants cuttings.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–27 . brush mats.8. cuttings. layering.2. Not tolerate alkaline sites. layering. December 1996) yes yes yes fibrous.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . brush mats. Use in combination with species with rooting ability good to excellent.16B–28 6.3. stakes. cuttings. cuttings. Under development in ID for riparian sites. 5. 9.8. poles. plants Plant materials type Occurs at high elevations. plants fascines. east of the Cascade Mtns. brush mats. stakes.4. 9.7. brush mats. layering. spreading fibrous fibrous shallow to deep v good v good v good exce Spread potential rapid fast rapid medium when young. stakes. brush mats.8. Roots only on lower 1/3 of cutting or at callus. Notes Streambank and Shoreline Protection medium to tall shrub medium shrub tall shrub to small tree large shrub Growth rate sandbar willow Rooting ability from cutting Salix interior Root type Region occurence Common name Scientific name Commer.0 1. 5. plants fascines.0 arroyo willow lemmon's willow shining willow Salix lasiolepis Salix lemmonii Salix lucida 1. poles.A (210-vi-EFH. layering.7.7. layering. poles. stakes. cuttings. layering. exigua. 'Rogue' cultivar released by OR PMC.4.0 8. poles. Thicket forming.3. plants fascines. 9. cuttings.9. medium thereafter medium medium fair Establishment speed fascines. This species has been changed to S.8. ‘Palouse’ cultivar released by WA PMC. poles. plants fascines. poles. brush mats. stakes. Susceptible to several diseases & insects. stakes. brush mats. 0 1. brush mats. lasiandra Root type Region occurence Common name Scientific name Commer. Needs full sun. sprouts readily fibrous good to excel v good v good fast fast medium medium to slow to slow Establishment speed good Spread potential fascines.6.8. Plant on 10. Notes Streambank and Shoreline Protection small to large tree medium to tall shrub large fibrous shrub to small tree Growth rate pacific willow Rooting ability from cutting Salix lucida ssp. Usually browsed by livestock.2. cuttings. stakes. layering. root cuttings. 9. Under development in ID for riparian sites.3. layering. There are several subspecies of S.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–29 . Survived 3 years of flooding in MS.7. 5. ‘Nehalem’ cultivar released by OR PMC.A yes yes (210-vi-EFH. layering. cuttings. plants Plant materials type May be short lived.5. Susceptible to several diseases and insects. shallow.to 12-foot spacing. A species for forested wetlands sites. 7. plants fascines. 8 yellow willow black willow Salix lutea Salix nigra 4.0. Under development in ID for riparian sites. December 1996) dense. lucida.4. cuttings.7.9.1. poles.8. sparingly escaped in the East.2. Often roots only at callus.3.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Spread potential fast poor medium poor Establishment speed fascines. poles. stakes.8. plants Plant materials type Pioneers on burned sites. stakes. 9. Tolerates partial shade. 'Streamco' cultivar released by NY PMC. poles. From Europe. plants fascines. 5 4. Notes Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook .7.A purpleosier willow scouler's willow Salix purpurea Salix scouleriana not yes native yes (210-vi-EFH. layering.0. brush mats. December 1996) large shrub to small tree medium tree large shrub to small tree shallow shallow fibrous. cuttings. layering. plants fascines. spreading v good excel good fast fast fast Growth rate laural willow Rooting ability from cutting Salix pentandra Root type Region occurence Common name Scientific name Commer. layering. cuttings. Occurs on both sides of the Cascade Mtns in low to high elevations. stakes. Insects may defoliate it regularly. brush mats. brush mats. cuttings.16B–30 1. poles. poles.0. fascines. brush mats. cuttings.3.0. 'Plumas' cultivar released by OR PMC. mexicana. Notes fascines. stakes. Softwood cuttings root easily in spring or summer.7.A (210-vi-EFH.2. Pith white.H 1. callicarpa.2.8.7. plants Plant materials type Streambank and Shoreline Protection medium shrub large shrub large shrub medium shrub very large shrub Growth rate sitka willow Rooting ability from cutting Salix sitchensis Root type Region occurence Common name Scientific name Commer.A american elder blue elderberry mexican elder red elderberry Sambucus canadensis Sambucus cerulea Sambucus cerulea ssp. This may be S. root root easily in plants spring or summer. 9. plants fascines. fascines. layering. Vigorous shoots branch freely. Softwood cuttings cuttings.8.8. lends itself to bioengineering uses. 8. layering. December 1996) yes yes yes yes fibrous fibrous & stoloniferous good good poor good v good v fast fast medium slow v fast fast rapid medium when young.1. mexicana Sambucus racemosa 9. 4.6.7. plants Softwood cuttings root easily in spring or summer. 0. brush mats. Was S. 9.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–31 . excellent survival in trials.0 6. cuttings. medium thereafter Establishment speed poor poor Spread potential Occurs on both sides of the Cascade Mtns.5. Pith brown. 4.9 6. plants Evergreen.3. brush mats. Softwood cuttings root easily in spring or summer.3. usually within 10 miles of the ocean & on the coastal bays & estuaries.3. Occurs east of the Cascade Mtns at medium to high elevations.2.2. division of suckers. pubens Root type Region occurence Common name Scientific name Commer. Use in combination with species with rooting ability good to excellent.16B–32 1. Plant materials type excellent fascines. suckering dense shallow. lateral deep laterals good fair to good fair to good rapid fast medium Establishment speed Notes plants plants Resists fire & prolific sprouter (forms thickets). Pith brown.3. Propagation by leafy softwood cuttings in midsummer under mist. Occurs west of the plants Cascade Mtns. 9 2. 4 1. Usually grown from seed.4. fascines.9. Propagation by leafy softwood cuttings in midsummer under mist.9.2. December 1996) yes yes fibrous. plants Spread potential Streambank and Shoreline Protection small dense shrub shrub short dense tree medium shrub Growth rate red elder Rooting ability from cutting Sambucus racemosa ssp.A (210-vi-EFH. cuttings. 0 meadowsweet spirea shinyleaf spirea douglas spirea Spiraea alba Spiraea betulifolia Spiraea douglasii 1.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook . 4. layering. 'Bashaw' cultivar released by WA PMC. dense colony forming large shrub shallow fibrous tap with laterals for knees for aeration shallow.2. Plant in sun to part brush shade. especially on mats. shallow poor poor good poor poor to fair slow medium rapid slow fast slow Establishment speed low poor fair Spread potential Propagation by leafy softwood cuttings in midsummer under mist. freely suckering dense.3. 9. 5. fibrous. A weed in New England pastures.6 Taxodium distichum Symphoricarpos snowberry albus Styrax japonica 1.to 12foot spacing.4.3.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook 16B–33 . Tolerates upland sites in region 6 with 32" rainfall. Notes plants plants Plant on 10. 5. wet sites. cuttings.3.3 baldcypress eastern hemlock Tsuga canadensis 1. December 1996) 1.2.8.6 1.0. Use rooted materials.A 1.2.7. 5 large tree medium tree small shrub. 5.Japanese snowbell (210-vi-EFH. fascines. layering.2. plants plants plants Plant materials type Streambank and Shoreline Protection yes yes yes yes small shrub Growth rate hardhack spirea Rooting ability from cutting Spiraea tomentosa Root type Region occurence Common name Scientific name Commer.3. Thicket forming. layering. 4.2.3 1. Branch tips root at soil. cuttings. tolerates city smoke.2. plants Plant materials type Streambank and Shoreline Protection large shrub medium shrub medium to tall shrub large tree Growth rate american elm Rooting ability from cutting Ulmus americana Root type Region occurence Common name Scientific name Commer.3. December 1996) shallow shallow.9 arrowwood hubblebush viburnam nannyberry Viburnum dentatum Viburnum lantanoides Viburnum lentago 1. Survived near 2 years of flooding in MS. brush mats.3.2. alnifolium. 4. Tolerates full shade. Was V. Thicket forming. tolerates city plants smoke.3. Notes fascines. fibrous tap on dry sites to shallow fibrous on moist sites fair to good good good poor fast fast medium Spread potential fast slow medium poor Establishment speed A species for forested wetland sites. 8 yes yes yes (210-vi-EFH.16B–34 1. Use in combination with species with rooting ability good to excellent. layering. Plant on 10.6. Older branches often root when they touch soil. stakes.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 Chapter 16 Part 650 Engineering Field Handbook .5. tolerates full shade. cuttings. 6 1.to 12-foot spacing. plants fascines. fibrous shallow. cuttings.5. Use rooted plant materials. stakes. plants Thicket forming.2. Fruits are edible.4.2. plants Plant materials type Chapter 16 Streambank and Shoreline Protection (210-vi-EFH. Notes layering. December 1996) Part 650 Engineering Field Handbook 16B–35 .6 1.Plant type cial availability Woody plants for soil bioengineering and associated systems—Continued Table 16B–1 slow Establishment speed Spread potential D.1. Wymann says it is more adapted to the South than V. 5. cassinoides.3. Use rooted plant plants materials.9 american cranberrybush Viburnum trilobum yes medium shrub large shrub poor poor medium Growth rate swamp haw Rooting ability from cutting Viburnum nudum Root type Region occurence Common name cientific name Commer. strigosus Rubus spectabilis Salix X cottetii Salix amygdaloides 16B–36 Common name Scientific name vine maple seepwillow eastern baccharis coyotebush water wally mulefat baccharis buttonbush silky dogwood roughleaf dogwood stiff dogwood gray dogwood roundleaf dogwood red-osier dogwood black twinberry pacific ninebark common ninebark narrowleaf cottonwood balsam poplar eastern cottonwood fremont cottonwood black cottonwood baldhip rose nootka rose swamp rose virginia rose woods rose allegheny blackberry red raspberry salmonberry dwarf willow peachleaf willow Salix bonplandiana Salix discolor Salix drummondiana Salix eriocephala Salix exigua Salix gooddingii Salix hookeriana Salix humilis Salix interior Salix lasiolepis Salix lemmonii Salix lucida Salix lucida ssp. December 1996) Common mame pussy willow pussy willow drummond's willow erect willow coyote willow goodding willow hooker willow prairie willow sandbar willow arroyo willow lemmon’s willow shining willow pacific willow yellow willow black willow laural willow purpleosier willow scouler’s willow sitka willow american elder mexican elder red elderberry red elder meadowsweet spirea douglas spirea snowberry arrowwood hubblebush viburnam nannyberry .Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Table 16B–2 Woody plants with fair to good or better rooting ability from unrooted cuttings Scientific name Acer circinatum Baccharis glutinosa Baccharis halimifolia Baccharis pilularis Baccharis salicifolia Baccharis viminea Cephalanthus occidentalis Cornus amomum Cornus drummondii Cornus foemina Cornus racemosa Cornus rugosa Cornus sericea ssp sericea Lonicera involucrata Physocarpus capitatus Physocarpus opulifolius Populus angustifolia Populus balsamifera Populus deltoides Populus fremontii Populus trichocarpa Rosa gymnocarpa Rosa nutkana Rosa palustris Rosa virginiana Rosa woodsii Rubus allegheniensis Rubus idaeus ssp. lasiandra Salix lutea Salix nigra Salix pentandra Salix purpurea Salix scouleriana Salix sitchensis Sambucus canadensis Sambucus cerulea ssp. pubens Spiraea alba Spiraea douglasii Symphoricarpos albus Viburnum dentatum Viburnum lantanoides Viburnum lentago (210-vi-EFH. mexicana Sambucus racemosa Sambucus racemosa ssp. December 1996) oceanspray sweet gallberry possomhaw bitter gallberrry american holly winterberry yaupon black walnut eastern redcedar leucothoe spicebush sweetgum tulip poplar fetterbush sweetbay southern waxmyrtle swamp tupelo ogeeche lime blackgum hophornbeam redbay lewis mockorange mallow ninebark common ninebark loblolly pine water elm sycamore quaking aspen wild plum 16B–37 . lasiocarpos Holodiscus discolor Ilex coriacea Ilex decidua Ilex glabra Ilex opaca Ilex verticillata Ilex vomitoria Juglans nigra Juniperus virginiana Leucothoe axillaris Lindera benzoin Liquidambar styraciflua Liriodendron tulipifera Lyonia lucida Magnolia virginiana Myrica cerifera Nyssa aquatica Nyssa ogeeche Nyssa sylvatica Ostrya virginiana Persea borbonia Philadelphus lewesii Physocarpus malvaceus Physocarpus opulifolius Pinus taeda Planera aquatica Platanus occidentalis Populus tremuloides Prunus angustifolia (210-vi-EFH.Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Table 16B–3 Woody plants with poor or fair rooting ability from unrooted cuttings Scientific name Acer glabrum Acer negundo Acer rubrum Acer saccharinum Alnus pacifica Alnus rubra Alnus serrulata Alnus viridis ssp.sinuata Amelanchier alnifolia var cusickii Amorpha fruitcosa Aronia arbutifolia Asimina triloba Betula nigra Betula papyrifera Betula pumila Carpinis caroliniana Carya aquatica Carya cordiformis Carya ovata Catalpa bignonioides Celtis laevigata Celtis occidentalis Cercis canadensis Chionanthus virginicus Clematis ligusticifolia Clethera alnifolia Cornus florida Cornus stricta Crataegus douglasii Crataegus mollis Cyrilla racemiflora Diospyros virginiana Dlaeagnus commutata Forestiera acuminata Fraxinus caroliniana Fraxinus latifolia Common name dwarf maple boxelder red maple silver maple pacific alder red alder smooth alder sitka alder cusick's serviceberry false indigo red chokeberry pawpaw river birch paper birch low birch american hornbeam water hickory bitternut hickory shagbark hickory southern catalpa sugarberry hackberry redbud fringetree western clematis sweet pepperbush flowering dogwood swamp dogwood douglas' hawthorn downy hawthorn titi persimmon silverberry swamp privet carolina ash oregon ash Scientific name Common mame Fraxinus pennsylvanica Gleditsia triacanthos Hibiscus aculeatus Hibiscus laevis green ash honeylocust hibiscus halberd-leaf marshmallow common rose mallow hibiscus Hibiscus moscheutos Hibiscus moscheutos ssp. Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook Table 16B–3 Woody plants with poor or fair rooting ability from unrooted cuttings—Continued Scientific name Prunus virginiana Quercus alba Quercus bicolor Quercus garryana Quercus laurifolia Quercus lyrata Quercus macrocarpa Quercus michauxii Quercus nigra Quercus pagoda Quercus palustris Quercus phellos Quercus shumardii 16B–38 Common name common chokecherry white oak swamp white oak oregon white oak swamp laurel oak overcup oak bur oak swamp chestnut oak water oak cherrybark oak pin oak willow oak shumard oak Scientific name Common mame Rhododendron atlanticum Rhododendron viscosum Rhus copallina Rhus glabra Robinia pseuodoacacia Sambucus cerulea Spiraea tomentosa Styrax americanus Taxodium distichum Tsuga canadensis Ulmus americana Viburnum nudum Viburnum trilobum coast azalea swamp azalea flameleaf sumac smooth sumac black locust blue elderberry hardhack spirea Japanese snowbell bald cypress eastern hemlock american elm swamp haw american cranberrybush (210-vi-EFH. December 1996) . ni H.5 pH preference good good fair good good fair Drought tolerance good poor good poor poor poor Shade tolerance poor poor fair poor good Deposition tolerance fair poor good poor fair Flood tolerance Flood season 0 0 0 0 0 0 Min.5 6.facu 7.fac6. h2o 1" Max. h2o 1.facw C.fac8.fac 3.facu 5.facw 6.fac+ 7.facw 3.0 6.0 6.facu2.upl 3.facw 0.facu 9facu 1.upl* Wetland indicator 1/ Streambank and Shoreline Protection Elymus virginicus sandy big bluestem Andropogon gerardii Arundo donax giant reed loams American beachgrass Ammophila breviligulata yes sands redtop Soil preference Agrostis alba Warm season or noncompetitive Common name Scientific name Table 16B–4 Grasses and forbs useful in conjunction with soil bioengineering and associated systems Chapter 16 Part 650 Engineering Field Handbook 16B–39 .facw- 1.0 5.facu2.facu 1.ni 1.fac 2.(210-vi-EFH.facw 8.0 7.fac4. December 1996) sand lovegrass Eragrostis trichodes yes sands yes loams noncompetitive Festuca rubra red fescue noncompetitive loams wildrye 6. ni 1.fac 6.ni H.ni 2.facw Wetland indicator 1/ Streambank and Shoreline Protection sandy loams to sands sandy limpograss Soil preference Hemarthria altissima Warm season or noncompetitive Common name Scientific name Table 16B–4 Grasses and forbs useful in conjunction with soil bioengineering and associated systems—Continued Chapter 16 Part 650 Engineering Field Handbook .facw 7.fac+ 3. h2o 2' 1' 1' Max.ni 1.fac+ 8.16B–40 sands to loams yes yes yes coastal panicgrass deertongue switchgrass seashore paspalum elephantgrass Panicum amarulum Panicum clandestinum Panicum virgatum Paspalum vaginatum Pennisetum purpureum 6.fac 9.facu+ C.facw 6. December 1996) poor poor poor poor poor Shade tolerance fair fair poor Deposition tolerance good good good good Flood tolerance all Flood season 0 1/2' 0 0 0 Min.fac+ H.0 5.facw* C.fac 2.facu- 1.fac 6.5 pH preference good good poor Drought tolerance (210-vi-EFH.facw 2. h2o 2.ni H.fac 5.facu2.obl 6.fac+ 4. 0 6.obl 6.facu Wetland indicator 1/ Chapter 16 Streambank and Shoreline Protection Part 650 Engineering Field Handbook 16B–41 .facw 6.obl 3.facu 1.upl 1.3-6.5 6.facw 8.facw 5.5 pH preference poor fair poor poor poor Shade tolerance fair poor poor poor Deposition tolerance good fair poor poor fair Flood tolerance all Flood season Table 16B–4 Grasses and forbs useful in conjunction with soil bioengineering and associated systems—Continued 1/2' 0 0 0 0 Min.Kentucky bluegrass Poa pratensis prairie cordgrass giant cutgrass Zizaniopsis miliacea Indiangrass Spartina pectinata Sorghastrum nutans Schizachyrium little scoparium bluestem Common name Scientific name yes yes yes Warm season or noncompetitive (210-vi-EFH.obl 1.facw+ 4.5 6.obl 9.facw+ 7.obl 2.obl 2.obl 3. h2o 2' 1" Max.0 poor 6. December 1996) loam sands to loams sands to sands to loams loam Soil preference good fair good poor Drought tolerance 4. h2o 1.obl 1. TN. IN) 4 North Plains (ND. 1988): Region code number or letter: 1 Northeast (ME. IL. WI. obl Obligate wetland—Occur almost always (99%) under naturl conditions in wetlands. DE. AR) 3 North Central (MO. KY. MT (eastern). VI. IA. December 1996) Part 650 Engineering Field Handbook . CT. NJ. GA.16B–42 Common name Warm season or noncompetitive Soil preference pH preference Drought tolerance Shade tolerance Deposition tolerance Flood tolerance Flood season Min. IQ. YQ) Indicator categories (estimated probability): fac Facultative—Equally likely to occur in wetlands or nonwetlands (34-66%). facu Facultative upland—Usually occur in nonwetlands (67-99%). AL. NY. SD. but occasionally found in wetlands (1-33%) facw Facultative wetland—Usually occur in wetlands (67-99%). CZ. PA. SC. UT. SQ) H Hawaii (HI. CO (western)) 9 Northwest (WA. MI. FL. OR. MA. RI. CO (eastern)) 6 South Plains (TX. ID. GU. but occur almost always (99%) under natural conditions in nonwetlands im˛QæB˛regioK˛QpC Ûh”DGed-˛'e˛` Qpec%Cs BMeQ nMt Mccur %n wetlands in any region. WV. h2o Max. MD. VT. ni (no indicator) indicates insufficient information was available to determine an indiator status. LA. * (asterisk) indicates wetlands indicators were derived from limited ecological information. upl Obligate upland—Occur in wetlands in another region. KS. WY (western)) 0 California (Ca) A Alaska (AK) C Caribbean (PR. h2o Wetland indicator 1/ 1/ Wetland indicator terms (from USDI Fish and Wildlife Service's National List of Plant Species That Occur in Wetlands. it is not on the National List. MT (western). VA. NM) 8 Intermountain (NV. MN. Scientific name Table 16B–4 Grasses and forbs useful in conjunction with soil bioengineering and associated systems—Continued Chapter 16 Streambank and Shoreline Protection (210-vi-EFH. WY (eastern)) 5 Central Plains (NE. + (positive sign) indicates more frequently found in wetlands. AQ. TQ. WQ. OK) 7 Southwest (AZ. OH) 2 Southeast (NC. Frequency of occurrence: – (negative sign) indicates less frequently found in wetlands. but occasionally found in nonwetlands. MQ. MS. NH.